The manufacturers have generally already maximized the transfer port and enlarging may only reduce velocity. To increase velocity a shorting of the piston head will increase swept volume resulting in increased velocity. Also in creasing spring strength or adding washers to increase velocity may provide a small increase but usually at the expense of smooth firing behavior ie more recoil, rough shooting,ruining accuracy. Some of this I found out through experience and some by reading.
@@BROTUNED this reminds me of real firearms that have to use different gunpowders to get different performances. The gunpowder of a pistol is much different than a rifle because of the difference of the barrel lengths. Therefore the gunpowder of a pistol is more explosive than that of a rifle to get the bullet out fast enough. The rifle on the other hand can best utilize a slower burn to create building up pressure taking advantage of the longer barrel. Pistol gunpowders in a rifle creates all sorts of problems for example the m16 during the Vietnam war. A larger exit hole in a pellet rifle should release greater gas pressure but perhaps more explosively instead of a rapid expansion. The small pellet can only accelerate so much before getting out of control.
If you shorten the piston, you will increase volume while cocked but then the piston will not go as far towards the transfer port, so at the point you literally went backwards.
@@Turbogto_guy Nope. The spring will reach the distance, it won't fall short at all, unless it was cut. Most springers are over sprung by the factory, so a modified piston will serve to improve firing behavior rather than adversely affecting fireing behavior. All this of coarse assumes that the smith has the requisite knowledge to execute the modification. Some do some don't. Some able and adventuresome individuals have done this with the Webley Tempest actually raising velocity from 420 fps to 500 fps. Some said it couldn't be done. But they were wrong.
I would recommend a transfer port size starting at 3.6 mm 4 at the very most. Also a stronger spring and washers stacked in the piston for weight. And some newer jsb pellets or h@n .
The big spring I put in on one of my newer vids made the rifle shoot worse I and going to switch it back out for my lighter one soon not sure if it’s recoil or harmonics but lost accuracy
I would never make the port larger than a pellet. If a pellet falls out of the chamber and back into the compression chamber, you'll dry fire the gun, you will miss your shot, and now you have to take apart the rifle to get a squished pellet out of the gun.
@@BROTUNEDnot if it’s .191 inches (4851.4 mm) that’s bigger than a pellet a .177 caliber pellet is literally .177 inches (4.5mm) so not sure where you got .191 is smaller than .177 but it’s not..
You might be better of by threading the transfer port. That way you can insert different sized holed inserts so you can adjust the airflow depending on the pellet weight.
he can still do that and first you got to enlarge hole or no way ,,I tried all this in 80 s and I feel best mod was thicker /better spring , rubber o ring if your air rifle had leather one like many had 40 years ago ,, ,than we polished cylinder tested piston seals,piston weights ,, RESULT//other than much better thicker wire , imported/i lived in Yugoslavia than // or hardened original spring //schoolmate s father worked in nail /screw factory so they had pro tempering and hardening furnances/oil baths //much more stiff spring might brake in few 1000 shoots , and it had to be shortened a bit not to smash into cylinder end wall //this would close to double ,,power ,,no chronometers than //coca cola bottle on 10 /20 /30 40 meters was our ,,powermeter and / or 177 pellet boxes penetration // from 3 layers /so 1 can thru and into 2nd to 2 thru and into 3rd was best we did //we were 10 to 12 old at time //we were experimenting with 1 pellet , pushed 1 inch into barrel ,,few all striking matches heads added /or better tin toy gun caps material //,followed by another pellet //this can get up to 22 lr penetration , but will ruin piston seal ets since strange things happen when you fire ,,1 pellet go out ,,faaast other go to bits some go out some bask in cilynder //but it work it would be lethal ,,remember old spring air rifles had like 7 mm thick barrel walls so we than added some flash powder from crackers and last thing we poured slugs because pellets were coming out as shoot //we took 177 drill ,drill into hard wood pour lead to get ,,lead wire , than cut to length,and if too big diameter roll on table to get ideal caliber //THIS COULD PENETRATE 6 TO 10 INCHES OF DRY SPRUCE FLOORWOOD //MORE THAN 22 LR //
So what was the FPS spread before? There appears to be a 45fps or so spread now. We didn’t see so perhaps it was this variable before but a 7% variation between shots can’t be good for consistency. Not being critical but One must consider if a little slower with consistent accuracy is better or worse than faster with wondering. Thoughts?
I drilled out the port on my first air rifle(Gamo Shadow1000). I didn't have a chronograph, but before doing the mod, it wouldn't pierce an old rusted burn barrel at point blank... after the mod, it would pierce it form 10 feet.
Remember a smaller hole passes less air but at a greater speed whereas a larger hole passes more air but at slower speeds. It seems that given the results a few thou does make an improvement, the danger is thinking of making it bigger again when you may get to the point when you start going backwards! I always wondered if a truncated cone shaped piston head paired to a compression chamber the same shape would channel the compressed air better than a flat configuration??
My theory on this was to get as much air behind the pellet as possible since it will start moving down the bore at low pressure. With a larger port you can get more pressure behind the pellet before it leaves the barrel. It may be a bit harder on the rifle because the piston doesn’t have as much compressed air cushion when it hits the end of the chamber
I see your point. I wonder if a lead in to the hole would guide the air in better than straight drilled? Or even a truncated piston with matching chamber might give better air flow to the pellet. Interesting thoughts!!!
Ya I don’t know was just an idea so I tried it. I shoot it quite often at 50 yards in my backyard and I hit relatively small targets pretty easily so it works for me and my pest control needs
I found this channel because I was wondering the same thing about air rifle porting. I've tried many different things including making my own shorter piston in aluminum Tubing. Got in a few over 700 FPS, and with less recoil. But it needs to be stronger. Might need to have it made in TITANIUM Yesterday I put my stock piston with only the hole plugged back in. Original seal, but lubed with 20,000 weight diff lube available at my local hobby shop for 12 BUCKS. Plus you get a lot more than crosman sells you for 20. 600 FPS with one virtually free change in assembly. I thought the thicker lube might slow the piston, but he results are repeatable. Crosman lube takes me back below 500 FPS.
That’s awesome I like mine around 600 fps the best the recoil isn’t to hash and it’s still accurate. That’s super cool you made an aluminum piston and if you do the titanium one I’d love to hear the results. Cheers man and happy modding
@@BROTUNED I have another practically identical rifle to the one I changed the lube in. Only difference is I've shortened the stock piston which is giving me virtually identical muzzle velocities to the unit with the new lube. So, naturally I'll be switching up the lube in that one to see if I get even better results, you know, For Science. Need more data. The Crosman 0.177 Pointed, 7.4 grain seem to give me the most consistent velocities within +/- 5 fps. Everything matters when it comes to accuracy.
So I tried this on a snow peak SP 500 pistol .22 . And I didn't notice much of a difference shooting so I went the opposite way and reduce the size of the hole by using a setscrew that I rounded the tip off so it would be a hexagon shaped porthole. Before when I tried dieseling my little pistol it didn't work. But I can tell you know that after some lubrication sure Pops. Now I'm able to pierce piece of drywall with the Dolmed pellet. Again at all probably depends on many factors good thing it wasn't difficult to come up with an idea going smaller for the porthole. But thank you for your video I like the fact that you have an idea and you try it. It gave me inspiration to see what I can do to increase the performance on my pistol. Also I know definitely it has more power because I have a decent scope on my pistol. And after reducing the size of the hole, I had to adjust the vertical sight quite a lot. So I know for a fact the pallets are flying at the same altitude farther.
Thank you so much much man I really appreciate it hope you like the channel! Please like the vids and I have a subscriber give away coming up when I reach 5555 subs so comment to up your chances and once again I really appreciate it!
muzzle port does nothing //we did when young /8 to 12 /all and short of 2 pellets and primer powder mix in between ,plus pouring slugs 7 mm long so weight of 3 to 7 pellets /when with powder from toy gun plastic ammo , or best 6 mm flobert dinamit noble platzpatronen //the copper one tiny for 6 mm start guns // slug pushed half inch into barrel than some of this powder //can use mix with flash powder or even all strike match heads carefully crushed /and than follow with another pellet //START WITH PELLET /POWDER ,,TINY AMMOUNT LIKE 2 MATCH HEADS OR 1 PLASTIC COWBOY TIN GUN POWDER /THAN ANOTHER PELLET ,,THAN GO UP ,, WHEN PELLET THAT DOME OUT IS MOLTEN OR TURN INTO TINY SHOOT //SEE WHEN SHOOTIN AT PAPER 3 METERS OR SO ,,THAN START USING POURED OR ROLLED FROM LEAD WIRE SLUGS,,START 3 MM ,,GO UP TO 1 CM /AND INCREASE LOAD ,,YOU GO EASY TO POWER THAT WOULD KILL HUMAN ON 30 METERS //AND YES PREPARE FEW PISTON SEALS AND EVERY FEW 100 SHOOTS CLEAN LEAD OUT OF PISTON /CILINDER ,, AFTER FEW 100 I DO NOT GET WHY , BUT TRIGGER MECHANISM BRAKE //LOOK BACKHIT OF PISTON WAS HITTIN ON TRIGGER PARTS//BUT IN APOCALIPSE ,THIS IS STRONG ENAUGH TO KILL A LIGHT DEER OR MAN / UP TO 50 METERS NO QUESTIONS,,IT COULD PENETRATE 10 INCHES OF DRY SPRUCE WOOD AND COULD DO MORE ,,BUT WE DID NOT LOAD IT TO THAT POINT //POWDER EXTRACTION FROM TINY PLASTIC 4 MM TOY GUNS DID NOT GIVE A LOT OF POWDER //THAT S WHY WE STARTED ADDING FLASH POWDER //AND THAN WE HAD LUCK WE GREW UP TO SHOOT REAL GUNS BEFORE WE D GO TOO STRONG //
I find it weird that so many here in the comment section believe that a smaller transfer port makes the pellets faster. Anything smaller than caliber diameter is just additional resitance and therefore decreases velocity. Except for a tiny bit of underboring, because the port itself is dead volume. but other than that, 3,5mm works on any rifle, 177, or 22
@@BROTUNED On my gamo replay, i drilled it to 3.2mm and reduced the piston weight by 15 percent. I used an angle grinder to cut out a strip. The piston bounce that used to hurt my shoulder is gone, and there is no real forward recoil either. It's a lot more accurate now. Can't really compare the energy, because it used to diesel extremely before that mod. Furthermore, i cleaned it out and used silicone oil.
@@BROTUNED Lengthwise. the ends of the piston are wider and have to be left intact. The strip i cut out was approximately 2cm wide and was on the opposite side of the normal cutout.
I have a .22 Gamo Hunter Grizzly Pro, the porting opened till 3,8mm, and works perfectly. Believe me it works perfectly. With the same 9 grains pellets it made before 23Jouls right now doing about 37 to 40 jouls and beats 340ms because I can hear two times noise in the air, above 1000FPS I think you opened to much the Porting. After check a few videos I did find out the ideal bore will be around .132 around 3,3mm, i am using a 80kg Gas Ram.
Your mod is very aggressive! I've been modding a new Crosman F11 (495 FPS alleged) .22 cal airgun for the last two months, and found that a new piston is required, not just a gas ram, to get good FPS. I first tested shims of various depths & positions, finding the ideal shim for a new nitro piston to be 3mm. After 5mm, there is a loss of FPS. I upgraded the stock gas ram to a 60kg version, and there are no bleed holes in the piston, but the piston seems to be the cause of the slowdown. I use Crosman Premier 14.3gr pellets (as you know, .22's are heavier), and I could only get 430 FPS out of it stock. My shim testing of 3mm's (between the fat body of the gas ram & the anterior of the front of the piston) gave me a good 20 more FSP. With the new 60kg gas ram, I should be getting 750 FPS but I'm seeing 450-470 still, with very erratic performance. Still thinking it's the gas ram at fault, I ordered a 70kg one. I also ordered a new piston for a Benjamin Trail that should allow greater increases in FPS. There is so much at play - the length of the gas ram, the depth of its compression, the length of the ram stroke, the ideal pre-load, etc. With the new 60 kg gas ram in the stock piston & a shim of 3mm, I'm shooting 450-470 FPS. If the new gas ram & piston work together to give me the FPS I paid for, I'll finally look into adding girth to the transfer port. I'd get better FPS using the 9.7gr Gamo pellets, yes, but I want my generic, 14.3gr Crosman hollow points to get the advertised 495 FPS - consistently. Gains after that, I need a PAL license, which I'm applying for. His 7.9% increase of his transfer port in this video took his .177 (4.4958 mm) port hole up to 4.8514 mm. Now, he's proven the extra 7.9096 % girth gives him a ~50 FPS increase - but I'd like to know what experimentation you did to finally decide on your transfer port mod of 3.8mm (and your ideal 3.3mm). What was the port's calibre stock? There must be an ideal "transfer port -to- breech" ratio for .22 cal. Yours, at 3.8mm : 5.5mm, is a 40% ratio. At 3.3mm to 5.5mm, it's 30% ratio. What if your rifle had a 70kg gas ram? Would you open it wider for a weaker gas ram? Newer nitro-piston airguns tend to maximize for the best transfer port performance, and leave the gas ram + piston to determine the FPS. I wouldn't want to bore out & ruin my new airgun without reading others' findings first. Thanks, I know this post is old but you've got performance I want. A shimmed gas ram with 70kg should be getting more than 470 FP with 14.3gr pellets.
@@NunchucksHabitI have a Ruger impact elite .22 also. I'm hoping he responds soon 😂! I'm curious if more porting is good for this gun. The factory port is tiny. I wonder if a conical port from the inside would increase fps or just a straight through port at the aforementioned angle. Hmm. I'll post a up video soon probably next week.
@@Ebikemike00 Update on mine - I just needed a different piston. The piston I have now is considerably shorter (150mm vs the OEM's 196mm), made for a NP2 Benjamin. The 70kg gas ram is also 8.5mm shorter. This makes for a longer cocking swing, but it locks & releases perfectly. I'm testing soon with more shim options since the cocking angle might not be ideal for the piston. It's a lot of work & a lot of pellets, but I'm fascinated by how legally available parts can so drastically improve velocity. I'd say the average fps with 14gr pellets is now ~750fps. I usually get a couple of shots > 900 fps, but they tend to even out around 750-775. Not bad for a cruddy Canadianized 440 fps toy from Canadian Tire. That's the great thing about universality between US & Canadian models. 'Magnum' parts can be a drop-in fit in detuned airguns. I still want to try boring the intake port just a bit, so I can at least analyze potential gains with modest port widening. There's a lot more air being pushed into that intake port now with shorter ram & piston, and I'm going to disassemble again this week so I can assess the ratio of intake port diameter/depth vs. the 5.5mm breech. My rifle is much louder now, and seems to be pushing too much air through the small hole at once. Maybe I'll try with my slightly weaker 60kg gas ram. So many variations - I wish the math was already done.
@@NunchucksHabit so if I have a US impact max elite .22, which piston combo do I already have and which piston/ram combo should i get to achieve the 100+ fps gains you have? Details please and thanks in advance! 🍿 🍺
@@Ebikemike00 Since your rifle is a totally different brand, as long as it uses a 'gas ram' (nitrogen), you've likely got options. A brand with a wide array of products (like Crosman) will likely have a good variety of parts that are swappable between models. My Crosman F11 got 430 fps average with 14.33gr pellets. After doing the following, it now gets 750-800 fps. Once it gets > 500fps, it's officially a 'firearm' in Canada, so don't get yourself in trouble. There are 4 major ways to improve velocity: 1) Increase the *amount* of air being compressed by installing a shorter piston. The most effective overall. Cost: About $50. Gain: ~300fps. 2) Add 'pre-load' to the gas ram (shimming). I found 3mm was ideal & gave me ~25 fps. Cost: $1. 3) A stronger gas ram. Nitrogen gas rams available on Ebay. with lots more power. I got a 70kg ram, but it's a bit too powerful & there's a huge kick & lots of noise. Cost: $50. Gain: ~20fps with OEM piston. 4) Intake port boring. Every layer of hardened steel you bore out is permanent, so bore out your intake port in small increments. Keep boring it out until you no longer see improvements in velocity. It'll start getting slower if you continue. Check the diameter first, then ask communities what the diameter is on a full powered one. It might already be optimized. Every time you bore it, you have to fully disassemble & re-assemble the rifle. Cost: $? drill bits, time. Gain: No idea, that's too much work for me. Try shimming first. It's easy, it's cheap & you don't have to fully disassemble the rifle either. Boring out the intake port should be your last move, but it might help immensely. It takes less time to take a gun safety course than it does to do that, and a safety course allows you to get a PAL in Canada, which allows you to buy a high powered airgun. That costs $60 for the course, $70 for the application.
Old video post! I've been trying to mod my Crosman F11 .22 cal Canadian version (495 fps) for the last 3 months so it will actually get close to the 495 fps promised. Stock, it gets and avg of 441 fps with a 14.3 gr Crosman Premier hollow point pellet. I'm not getting my money's worth. Mods I'm doing are legal - I'm not exceeding the Canadian limit of 500 fps. I'm trying to improve the performance of this rifle to within the legal params. Stock Performance: Avg FPS with 17gr pellet: 390 fps (118.775 m/s) - Max: 395 fps Avg FPS with 14.3gr pellet: 441 fps (134.38 m/s) - Max: 452 fps EDIT: I managed to modify my Crosman F11 so it now gets 750 - 800 fps. Your response to this is still very good advice. I did not bore out the intake port. I'm sure I could gain more velocity by doing so, but like you said, it's permanent. The only way to know if you've gone too far is to keep going & as you know, each time you bore it out a bit more, you have to fully re-assemble it again. In order, I'd suggest: Shimming, replacing the piston, replacing the gas ram, then porting. A shim of 3mm gave me ~25fps gain. 6mm lost me 30 fps. Gas rams don't like too much preload, plus shimming decreases the overall volume of cubic air being compressed. It's a balance between pressure & volume & for this rifle, 3mm was best.
He’s a real dr. Suse. ! College boy . Need to work fer a ketchup company and design a new bottle that don’t squirt ketchup all over my dam clothes !!! By the way ; don’t reinvent the dam wheel. The old bottle with a dam hole in the end works perfectly fine . I know I’m off the subject; however it makes me feel so much better I I’m sure I’m not the only one . Can I get a a” man and a couple likes .
was the hole round before you enlarged it, I thought that the barrel side of the hole was supposed to be square. let me know because I might try this myself. cheers.
if your rifle is a .22 then drill out the transfer port no bigger than 4mm max a tapered drill hole from the inside of the air cylinder is far better than a Strate hole drilled from the outside, but any drill hole made must be smoothed bored. no ruff edge's in the hole, as they will cause turbulence and slow down the passage of compressed air, deburr all the edges. you will need a stronger faster spring, but do not overload the trigger sear, or the gun will become unsafe and will start discharging without warning, if this dose not give you enough power all you can do now is bore out the air cylinder and change the piston size for a bigger bore, so you get more air capacity out the cylinder, to improve FT,PS = more FT,LBS more air in needed to push the pellet, but not that much more presser,
enlargin port is on air guns that were poorly made ,, so it will not give you even as much speed boost as lubing the cylinder on 50 shoots or so //spring and piston seal change is only way to get more power that is noticeable //no chronny I mean it can brake glass bottle on 40 yards that could pre fix brake it on 20 yards tops// get a diana 450 magnum if 177 //and you got most that 177 can do //and you will grow some muscle cockin it //and 22 cal is I think called diana magnum 460 //and is a pinch stronger than 177 //not a lot but if into hunting crows,rabbits , etc it is close to 1000 or more dollar prefilled air rifle //but there you got to fill bottle , shoots are not consistent ,, and power is at maximum 1/3 stronger with using slugs that cost at least 10 time vs top pellets
By opening the cylinder this will cause it to loose fps , what some tuners do is to drill it out the cylinder much wider and sweat in a piece of metal or brass and drill it out small then the original hole .Nice video Cheers 🍻
I was thinking of it as in an engine where you port it go get a larger volume of air to pass through. The reason I thought this was the way to go it that the piston will compress to a certain degree then slow down because it can’t over power the compressed air with the small hole restricting flow. So I figured if I bore it out a bit it would allow more air at the same pressure behind the pellet causing it to push it a bit faster before it because the barrel releasing the pressure.
@BROTUNED I can see your thinking , example a lot of owners in the past were told to drill out the cylinder because their was a restriction build into to it , so by drilling it out , this would give the rifle more power out put , but in-fact it ruined the cylinder and many had to purchase new cylinders . So wider reducers power small producers more power . Cheers 🍻
couple issues here: increasing the "transfer port" diameter will NOT produce a higher velocity of air...it will ONLY increase the volume of air. So you have it backwards. If the goal is to create more pressure = a faster feet per second, then you would want a smaller diameter transfer port. but there are other physics that will control the actual maximum pressure. Most of this is due to variables that are not related to the size of the transfer port and have more to do with spring RATE and throw...as well as the size and fit of the pellet in the breech as well as the breech seal second, I noticed you did not actually duplicate the same conditions in the before and after chrony. Are they set at the same distance? in the same barometric pressure (one looks like inside in warm controlled environment with chrony set up near the clay target and the other right near the muzzle in very cold weather. yes these factors make a difference in feet per second measurements. Also, are you using the same exact pellet brand AND BATCH? another way to increase feet per second is to polish the inner charging barrel with "chrome polishing compound (never sand paper...that's just stupid!). the smoothness of the inner charging barrel will have less surface friction and the piston gasket can then accelerate with less resistance...producing a faster rate of pressure increase..... another way to increase feet per second is to change out the charging piston gasket/seal....there are some aftermarket designs that have better materials and fitment that allow the charging piston to travel faster (less resistance) and still maintain a very good seal. one way to deliver a faster feet per second is to simply use a lighter grain pellet weight. And there would be no need to make these kinds of modifications. Another way without modifying the "iron" is to simply upgrade the charging piston....swapping a springer to a nitrogen gas piston is probably the easiest and most reliable upgrade you can make to a standard springer to get a faster feet per second. And generally speaking, a nitrogen gas piston over a standard springer setup is going to get you less "noise" in terms of vibrations that affect accuracy.. gas pistons also generally do not have the loud "ring" that the standard springers do. speaking of pellets...almost all pellets vary in actual gauge size...And this matters quite a bit in terms of speed, accuracy and consistency. For instance, I have a benjamin trail np xl (.177/4,5 mm) that will shot tacks every day as long as I use a H&N 4.51 mm pellets...read it again..this is a pellet made by H&N that is slightly larger in diameter...4.51 mm...So it's a tighter fit. I've demonstrated in chrony, it is a faster and more accurate pellet than any other in the same 10.5 grain size. So size matters if you are after accuracy and consistent speed....conversely, I have never been able to shoot accurately with "vortex" branded pellets or rws ...they have a very loose fit. and they fly all over the paper and record quite fps spread....the crosman domed premieres do okay...but it is the 4.51 mm H&N's that are the cats pajamas.
Hi gentlemen I have a Canadian Benjamin Classic .22 with a 3.80mm hole because of you now at more or less 510 fpi thanks next mod Titan XS Springs..! keep up the good work and let us know thank you.
Honestly I have never tested any so I can’t answer your question. I have tried a few different springs from vortekproducts.com and everything went very smoothly.
I dont think it gained that much cause in the video the first test was indoors with less air volume than the ice cold air outside we all know the colder the air is inside the chamer the more power...i did port my gamo vipermax and saw little to no difference
Hello there my friend from Greece! It seems that only one person here in the chat section noticed it. You didn't show us the starting spread but after the mod you had an extreme spread of 46 fps between 672fps to 718 as we saw! This is a very different number than the manufacturers give us between 15-29 fps. You gained a bit of power but if you do some target shooting now, will be like firing a shotgun with round balls to your target! :)
@@BROTUNEDDid it settle down , after how many shots? Maybe after the swarves have gotten themselves out of the chamber slowly? What fps spread do you have now?
It can take quit some shots before all oil residues have dieseled away. I noticed the same when working on my PCP's, a lot more spread on the first 10 shots, after that the rifle settles down and becomes more constant.
How old is this tin of pellet ? Mines are marked 7.9gr! I am surprised it increased the velocity the port looked already pretty big ! (or all the pictures are after the drilling?) I think I couldnt even get a toothpick in a Gamo port so im starting to believe this may be the only thing detuning them I dont think Crosman is using different port size for both versions tho !
I’m looking for a spring upgrade for my Crosman Optimus .177 495fps. What kind of spring do I need to get for more fps? I have no idea what I’m looking for online. Is there a certain size or length I need? Any help would be appreciated and great video.👍🏼
I get mine from vortekproducts.com I can tell you the exact spring I got but basically what I did was pulled the stock spring out and measured it’s length and wire thickness and added a few coils to it. Then I fit it in the air gun and if it got spring bind before it was cocked I would disassemble it again and cut a coil off of the spring until I had the longest spring that would fit without binding up and that’s about it.
I bought a brand new spring for the Crosman Optimus a few years ago from Canada Shooting Supply - it is the high power 1200fps spring and it comes with brand new piston and seal - I originally bought it to swap out the weak spring in my 495fps Crosman Phantom but never ever got around to doing it. I cant tell you the exact specs of the spring off hand.. but it was cheap to buy and a better option than trying to stretch out your original spring. Check Canada Shooting Supply and see if they still have them in stock.
Ya lost accuracy big time and went back to around 650 fps and almost thinking of dropping it back to around 500. Makes it a lot easier to shoot well and if it’s for critters that will have no issue taking care of them.
@BROTUNED Yeah it's all about finding the balance with springers, some guns that tune really well it's possible to get a bit more power and a smoother shot cycle but would take a fair bit of polishing up.
@BROTUNED It is expensive but I'm not a big fan of pcps, they just feel dead to me, higher powered ones are gonna have a bit of kick though. I just love spring guns.
@@BROTUNED many people say that if you have an air rifle 4.5mm the maximum opening in a tube hole is 3.8mm. I drilled it to 4.5mm and I do not know if it gets more fps or lose fps
So I'm wondering if you paint an air rifle with a rubberized coating if it will deaden piston slap. Ive read a lot of people saying that porting can ruin many rifles but I've wondered about polishing and beveling the port for less angle of extry.
The air rifle companies have maximized the blow through holes on the piston chamber sides. My advice would be get a more powerful air rifle,rebuild the piston, or upgrade the model with performance parts where applicable! Ruining the air rifle proves nothing but ignorance. You can always upgrade to an Pcp air rifle for superior performance.
I tuned my webly falcon spring gun up ox spring drilled out the air release hole slightly bigger washers behind the spring got stopped by police out shooting rabbits thay tested my gun it was 16 ftpound the leagle limit in Britain is 12 I was arrested gun conferscated I had no idea of the laws bk then they set anything over 12 u need a fire arm certificate
Drilling a transfer port on an airgun is probably the worst idea of all. Think of it as a blowpipe, you want the maximum of air passing very quickly trough the smalest hole possible. Or try to think of what your mouth does when you spit far, now imagine spitting with your mouth fully opened...see where I'm going ? Most guns already have the transfer port maximised, tho you may gain some fps if lucky, you have more chances of ruining the gun or making it shoot LESS fast... Believe me I tried 🤦🤦🤦 fawk me
I understand what you’re saying but it’s cheap gun and I’m experimenting with it . Not to worried about it but it does shoot better now. I think I’m going to put a lighter weight spring back in it though the recoil is getting ridiculous the heavier I go.
@@BROTUNED If you want to open the port they do not recommend going higher than 80% of the pellet squirt diameter. Under that is OK I guess ... 🤷 I know what you mean about the crazy recoil. All the guns I buy are under 500fps without a licence (heh Canada), tho they do shoot very smoothly right out of the box, then I try my best to bring them as close as I can to the legal capacity. Most of the time I just end-up with a gun that's too powerfull to stay legal with an unpleasant "boïoïoïong" effect. The fix to that is to fit a gas ram instead of a spring. The best way to gain a lot of power (you have already done) is to plug the hole in the piston. You get on average 200 more fps. Also you can literally bathe the spring in grease, polish the piston with a very fine sandpaper and lightly grease it also. Check if the chamber is free of sand or other particles. You can gain an additionnal 30-60 fps just by eliminating metal friction. ✌
@@BROTUNED apparently I've seen vids saying it will increase from 800 fps to 1000+ fps.. I'll do it after the festive season, when I'm not drunk anymore.
The manufacturers have generally already maximized the transfer port and enlarging may only reduce velocity. To increase velocity a shorting of the piston head will increase swept volume resulting in increased velocity. Also in creasing spring strength or adding washers to increase velocity may provide a small increase but usually at the expense of smooth firing behavior ie more recoil, rough shooting,ruining accuracy. Some of this I found out through experience and some by reading.
Ya I tried a big heavy spring and wasn’t impressed by the recoil and loss of accuracy. To be honest it shoots best at around 550 fps
@@BROTUNED this reminds me of real firearms that have to use different gunpowders to get different performances. The gunpowder of a pistol is much different than a rifle because of the difference of the barrel lengths. Therefore the gunpowder of a pistol is more explosive than that of a rifle to get the bullet out fast enough. The rifle on the other hand can best utilize a slower burn to create building up pressure taking advantage of the longer barrel. Pistol gunpowders in a rifle creates all sorts of problems for example the m16 during the Vietnam war. A larger exit hole in a pellet rifle should release greater gas pressure but perhaps more explosively instead of a rapid expansion. The small pellet can only accelerate so much before getting out of control.
If you shorten the piston, you will increase volume while cocked but then the piston will not go as far towards the transfer port, so at the point you literally went backwards.
@@Turbogto_guy Nope. The spring will reach the distance, it won't fall short at all, unless it was cut. Most springers are over sprung by the factory, so a modified piston will serve to improve firing behavior rather than adversely affecting fireing behavior. All this of coarse assumes that the smith has the requisite knowledge to execute the modification. Some do some don't. Some able and adventuresome individuals have done this with the Webley Tempest actually raising velocity from 420 fps to 500 fps. Some said it couldn't be done. But they were wrong.
@@neilplace7916 I’ll take mine apart tonight and see what I can do with it. Was thinking a lighter piston would help too.
I would recommend a transfer port size starting at 3.6 mm 4 at the very most. Also a stronger spring and washers stacked in the piston for weight. And some newer jsb pellets or h@n .
The big spring I put in on one of my newer vids made the rifle shoot worse I and going to switch it back out for my lighter one soon not sure if it’s recoil or harmonics but lost accuracy
@@BROTUNED this is usually the case ,
@@BROTUNEDqp
I would never make the port larger than a pellet. If a pellet falls out of the chamber and back into the compression chamber, you'll dry fire the gun, you will miss your shot, and now you have to take apart the rifle to get a squished pellet out of the gun.
I made the port a bit smaller than the bore of the barrel
But ya that would definitely suck
@@BROTUNEDnot if it’s .191 inches (4851.4 mm) that’s bigger than a pellet a .177 caliber pellet is literally .177 inches (4.5mm) so not sure where you got .191 is smaller than .177 but it’s not..
You might be better of by threading the transfer port. That way you can insert different sized holed inserts so you can adjust the airflow depending on the pellet weight.
That’s a great idea! Thanks I will have to look into this
This is what I need to test "rocket nozzle" port shapes!
@@hansjohannsen6722 Has been done numerous times, nothing to be gained.
he can still do that
and first you got to enlarge hole or no way ,,I tried all this in 80 s and I feel best mod was thicker /better spring , rubber o ring if your air rifle had leather one like many had 40 years ago ,, ,than we polished cylinder tested piston seals,piston weights ,, RESULT//other than much better thicker wire , imported/i lived in Yugoslavia than // or hardened original spring //schoolmate s father worked in nail /screw factory so they had pro tempering and hardening furnances/oil baths //much more stiff spring might brake in few 1000 shoots , and it had to be shortened a bit not to smash into cylinder end wall //this would close to double ,,power ,,no chronometers than //coca cola bottle on 10 /20 /30 40 meters was our ,,powermeter and / or 177 pellet boxes penetration // from 3 layers /so 1 can thru and into 2nd to 2 thru and into 3rd was best we did //we were 10 to 12 old at time //we were experimenting with 1 pellet , pushed 1 inch into barrel ,,few all striking matches heads added /or better tin toy gun caps material //,followed by another pellet //this can get up to 22 lr penetration , but will ruin piston seal ets since strange things happen when you fire ,,1 pellet go out ,,faaast other go to bits some go out some bask in cilynder //but it work it would be lethal ,,remember old spring air rifles had like 7 mm thick barrel walls so we than added some flash powder from crackers and last thing we poured slugs because pellets were coming out as shoot //we took 177 drill ,drill into hard wood pour lead to get ,,lead wire , than cut to length,and if too big diameter roll on table to get ideal caliber //THIS COULD PENETRATE 6 TO 10 INCHES OF DRY SPRUCE FLOORWOOD //MORE THAN 22 LR //
@@michomicho7668 Is this a sentence?
So what was the FPS spread before? There appears to be a 45fps or so spread now. We didn’t see so perhaps it was this variable before but a 7% variation between shots can’t be good for consistency. Not being critical but One must consider if a little slower with consistent accuracy is better or worse than faster with wondering. Thoughts?
Need to do more testing but it did shoot better with the lighter spring in it so going back to the light spring then I’ll test it again
I drilled out the port on my first air rifle(Gamo Shadow1000). I didn't have a chronograph, but before doing the mod, it wouldn't pierce an old rusted burn barrel at point blank... after the mod, it would pierce it form 10 feet.
That’s a great improvement in power for sure 👍🏻
Remember a smaller hole passes less air but at a greater speed whereas a larger hole passes more air but at slower speeds. It seems that given the results a few thou does make an improvement, the danger is thinking of making it bigger again when you may get to the point when you start going backwards! I always wondered if a truncated cone shaped piston head paired to a compression chamber the same shape would channel the compressed air better than a flat configuration??
My theory on this was to get as much air behind the pellet as possible since it will start moving down the bore at low pressure. With a larger port you can get more pressure behind the pellet before it leaves the barrel. It may be a bit harder on the rifle because the piston doesn’t have as much compressed air cushion when it hits the end of the chamber
I see your point. I wonder if a lead in to the hole would guide the air in better than straight drilled? Or even a truncated piston with matching chamber might give better air flow to the pellet. Interesting thoughts!!!
Ya I don’t know was just an idea so I tried it. I shoot it quite often at 50 yards in my backyard and I hit relatively small targets pretty easily so it works for me and my pest control needs
I found this channel because I was wondering the same thing about air rifle porting.
I've tried many different things including making my own shorter piston in aluminum Tubing. Got in a few over 700 FPS, and with less recoil. But it needs to be stronger. Might need to have it made in TITANIUM
Yesterday I put my stock piston with only the hole plugged back in. Original seal, but lubed with 20,000 weight diff lube available at my local hobby shop for 12 BUCKS. Plus you get a lot more than crosman sells you for 20.
600 FPS with one virtually free change in assembly. I thought the thicker lube might slow the piston, but he results are repeatable. Crosman lube takes me back below 500 FPS.
That’s awesome I like mine around 600 fps the best the recoil isn’t to hash and it’s still accurate. That’s super cool you made an aluminum piston and if you do the titanium one I’d love to hear the results. Cheers man and happy modding
@@BROTUNED I have another practically identical rifle to the one I changed the lube in. Only difference is I've shortened the stock piston which is giving me virtually identical muzzle velocities to the unit with the new lube. So, naturally I'll be switching up the lube in that one to see if I get even better results, you know, For Science. Need more data.
The Crosman 0.177 Pointed, 7.4 grain seem to give me the most consistent velocities within +/- 5 fps.
Everything matters when it comes to accuracy.
So I tried this on a snow peak SP 500 pistol .22 . And I didn't notice much of a difference shooting so I went the opposite way and reduce the size of the hole by using a setscrew that I rounded the tip off so it would be a hexagon shaped porthole. Before when I tried dieseling my little pistol it didn't work. But I can tell you know that after some lubrication sure Pops. Now I'm able to pierce piece of drywall with the Dolmed pellet. Again at all probably depends on many factors good thing it wasn't difficult to come up with an idea going smaller for the porthole.
But thank you for your video I like the fact that you have an idea and you try it. It gave me inspiration to see what I can do to increase the performance on my pistol. Also I know definitely it has more power because I have a decent scope on my pistol. And after reducing the size of the hole, I had to adjust the vertical sight quite a lot. So I know for a fact the pallets are flying at the same altitude farther.
That’s very cool you stepped it up and experimented
You just answered my question Thanks.
Man you are a technical guy i like it & you got a new subscriber
Thank you so much much man I really appreciate it hope you like the channel! Please like the vids and I have a subscriber give away coming up when I reach 5555 subs so comment to up your chances and once again I really appreciate it!
I've often wonder about a convergent/ divergent nozzle design port... It takes hip pressure low speed air and goes to space...
muzzle port does nothing //we did when young /8 to 12 /all and short of 2 pellets and primer powder mix in between ,plus pouring slugs 7 mm long so weight of 3 to 7 pellets /when with powder from toy gun plastic ammo , or best 6 mm flobert dinamit noble platzpatronen //the copper one tiny for 6 mm start guns // slug pushed half inch into barrel than some of this powder //can use mix with flash powder or even all strike match heads carefully crushed /and than follow with another pellet //START WITH PELLET /POWDER ,,TINY AMMOUNT LIKE 2 MATCH HEADS OR 1 PLASTIC COWBOY TIN GUN POWDER /THAN ANOTHER PELLET ,,THAN GO UP ,, WHEN PELLET THAT DOME OUT IS MOLTEN OR TURN INTO TINY SHOOT //SEE WHEN SHOOTIN AT PAPER 3 METERS OR SO ,,THAN START USING POURED OR ROLLED FROM LEAD WIRE SLUGS,,START 3 MM ,,GO UP TO 1 CM /AND INCREASE LOAD ,,YOU GO EASY TO POWER THAT WOULD KILL HUMAN ON 30 METERS //AND YES PREPARE FEW PISTON SEALS AND EVERY FEW 100 SHOOTS CLEAN LEAD OUT OF PISTON /CILINDER ,, AFTER FEW 100 I DO NOT GET WHY , BUT TRIGGER MECHANISM BRAKE //LOOK BACKHIT OF PISTON WAS HITTIN ON TRIGGER PARTS//BUT IN APOCALIPSE ,THIS IS STRONG ENAUGH TO KILL A LIGHT DEER OR MAN / UP TO 50 METERS NO QUESTIONS,,IT COULD PENETRATE 10 INCHES OF DRY SPRUCE WOOD AND COULD DO MORE ,,BUT WE DID NOT LOAD IT TO THAT POINT //POWDER EXTRACTION FROM TINY PLASTIC 4 MM TOY GUNS DID NOT GIVE A LOT OF POWDER //THAT S WHY WE STARTED ADDING FLASH POWDER //AND THAN WE HAD LUCK WE GREW UP TO SHOOT REAL GUNS BEFORE WE D GO TOO STRONG //
I find it weird that so many here in the comment section believe that a smaller transfer port makes the pellets faster. Anything smaller than caliber diameter is just additional resitance and therefore decreases velocity. Except for a tiny bit of underboring, because the port itself is dead volume. but other than that, 3,5mm works on any rifle, 177, or 22
That’s exactly my theory. It’s like porting and engine allowing a greater volume of air to flow through in a shorter amount of time.
@@BROTUNED
On my gamo replay, i drilled it to 3.2mm and reduced the piston weight by 15 percent. I used an angle grinder to cut out a strip. The piston bounce that used to hurt my shoulder is gone, and there is no real forward recoil either. It's a lot more accurate now. Can't really compare the energy, because it used to diesel extremely before that mod. Furthermore, i cleaned it out and used silicone oil.
Where did you cut out lengthwise along the piston body or across it?
@@BROTUNED
Lengthwise. the ends of the piston are wider and have to be left intact. The strip i cut out was approximately 2cm wide and was on the opposite side of the normal cutout.
@leod1961 thanks for the info I’m going to look into this
I have a .22 Gamo Hunter Grizzly Pro, the porting opened till 3,8mm, and works perfectly.
Believe me it works perfectly.
With the same 9 grains pellets it made before 23Jouls right now doing about 37 to 40 jouls and beats 340ms because I can hear two times noise in the air, above 1000FPS
I think you opened to much the Porting.
After check a few videos I did find out the ideal bore will be around .132 around 3,3mm, i am using a 80kg Gas Ram.
Your mod is very aggressive!
I've been modding a new Crosman F11 (495 FPS alleged) .22 cal airgun for the last two months, and found that a new piston is required, not just a gas ram, to get good FPS.
I first tested shims of various depths & positions, finding the ideal shim for a new nitro piston to be 3mm. After 5mm, there is a loss of FPS.
I upgraded the stock gas ram to a 60kg version, and there are no bleed holes in the piston, but the piston seems to be the cause of the slowdown.
I use Crosman Premier 14.3gr pellets (as you know, .22's are heavier), and I could only get 430 FPS out of it stock. My shim testing of 3mm's (between the fat body of the gas ram & the anterior of the front of the piston) gave me a good 20 more FSP. With the new 60kg gas ram, I should be getting 750 FPS but I'm seeing 450-470 still, with very erratic performance. Still thinking it's the gas ram at fault, I ordered a 70kg one. I also ordered a new piston for a Benjamin Trail that should allow greater increases in FPS. There is so much at play - the length of the gas ram, the depth of its compression, the length of the ram stroke, the ideal pre-load, etc.
With the new 60 kg gas ram in the stock piston & a shim of 3mm, I'm shooting 450-470 FPS. If the new gas ram & piston work together to give me the FPS I paid for, I'll finally look into adding girth to the transfer port. I'd get better FPS using the 9.7gr Gamo pellets, yes, but I want my generic, 14.3gr Crosman hollow points to get the advertised 495 FPS - consistently. Gains after that, I need a PAL license, which I'm applying for.
His 7.9% increase of his transfer port in this video took his .177 (4.4958 mm) port hole up to 4.8514 mm. Now, he's proven the extra 7.9096 % girth gives him a ~50 FPS increase - but I'd like to know what experimentation you did to finally decide on your transfer port mod of 3.8mm (and your ideal 3.3mm). What was the port's calibre stock? There must be an ideal "transfer port -to- breech" ratio for .22 cal. Yours, at 3.8mm : 5.5mm, is a 40% ratio. At 3.3mm to 5.5mm, it's 30% ratio. What if your rifle had a 70kg gas ram? Would you open it wider for a weaker gas ram?
Newer nitro-piston airguns tend to maximize for the best transfer port performance, and leave the gas ram + piston to determine the FPS. I wouldn't want to bore out & ruin my new airgun without reading others' findings first.
Thanks, I know this post is old but you've got performance I want. A shimmed gas ram with 70kg should be getting more than 470 FP with 14.3gr pellets.
@@NunchucksHabitI have a Ruger impact elite .22 also. I'm hoping he responds soon 😂! I'm curious if more porting is good for this gun. The factory port is tiny. I wonder if a conical port from the inside would increase fps or just a straight through port at the aforementioned angle. Hmm. I'll post a up video soon probably next week.
@@Ebikemike00 Update on mine - I just needed a different piston. The piston I have now is considerably shorter (150mm vs the OEM's 196mm), made for a NP2 Benjamin. The 70kg gas ram is also 8.5mm shorter. This makes for a longer cocking swing, but it locks & releases perfectly. I'm testing soon with more shim options since the cocking angle might not be ideal for the piston. It's a lot of work & a lot of pellets, but I'm fascinated by how legally available parts can so drastically improve velocity. I'd say the average fps with 14gr pellets is now ~750fps. I usually get a couple of shots > 900 fps, but they tend to even out around 750-775. Not bad for a cruddy Canadianized 440 fps toy from Canadian Tire. That's the great thing about universality between US & Canadian models. 'Magnum' parts can be a drop-in fit in detuned airguns.
I still want to try boring the intake port just a bit, so I can at least analyze potential gains with modest port widening. There's a lot more air being pushed into that intake port now with shorter ram & piston, and I'm going to disassemble again this week so I can assess the ratio of intake port diameter/depth vs. the 5.5mm breech. My rifle is much louder now, and seems to be pushing too much air through the small hole at once. Maybe I'll try with my slightly weaker 60kg gas ram. So many variations - I wish the math was already done.
@@NunchucksHabit so if I have a US impact max elite .22, which piston combo do I already have and which piston/ram combo should i get to achieve the 100+ fps gains you have? Details please and thanks in advance! 🍿 🍺
@@Ebikemike00 Since your rifle is a totally different brand, as long as it uses a 'gas ram' (nitrogen), you've likely got options. A brand with a wide array of products (like Crosman) will likely have a good variety of parts that are swappable between models.
My Crosman F11 got 430 fps average with 14.33gr pellets. After doing the following, it now gets 750-800 fps. Once it gets > 500fps, it's officially a 'firearm' in Canada, so don't get yourself in trouble.
There are 4 major ways to improve velocity:
1) Increase the *amount* of air being compressed by installing a shorter piston. The most effective overall. Cost: About $50. Gain: ~300fps.
2) Add 'pre-load' to the gas ram (shimming). I found 3mm was ideal & gave me ~25 fps. Cost: $1.
3) A stronger gas ram. Nitrogen gas rams available on Ebay. with lots more power. I got a 70kg ram, but it's a bit too powerful & there's a huge kick & lots of noise. Cost: $50. Gain: ~20fps with OEM piston.
4) Intake port boring. Every layer of hardened steel you bore out is permanent, so bore out your intake port in small increments. Keep boring it out until you no longer see improvements in velocity. It'll start getting slower if you continue. Check the diameter first, then ask communities what the diameter is on a full powered one. It might already be optimized.
Every time you bore it, you have to fully disassemble & re-assemble the rifle.
Cost: $? drill bits, time. Gain: No idea, that's too much work for me.
Try shimming first. It's easy, it's cheap & you don't have to fully disassemble the rifle either. Boring out the intake port should be your last move, but it might help immensely.
It takes less time to take a gun safety course than it does to do that, and a safety course allows you to get a PAL in Canada, which allows you to buy a high powered airgun. That costs $60 for the course, $70 for the application.
Old video post!
I've been trying to mod my Crosman F11 .22 cal Canadian version (495 fps) for the last 3 months so it will actually get close to the 495 fps promised. Stock, it gets and avg of 441 fps with a 14.3 gr Crosman Premier hollow point pellet. I'm not getting my money's worth.
Mods I'm doing are legal - I'm not exceeding the Canadian limit of 500 fps. I'm trying to improve the performance of this rifle to within the legal params.
Stock Performance:
Avg FPS with 17gr pellet: 390 fps (118.775 m/s) - Max: 395 fps
Avg FPS with 14.3gr pellet: 441 fps (134.38 m/s) - Max: 452 fps
EDIT: I managed to modify my Crosman F11 so it now gets 750 - 800 fps. Your response to this is still very good advice. I did not bore out the intake port. I'm sure I could gain more velocity by doing so, but like you said, it's permanent. The only way to know if you've gone too far is to keep going & as you know, each time you bore it out a bit more, you have to fully re-assemble it again.
In order, I'd suggest: Shimming, replacing the piston, replacing the gas ram, then porting. A shim of 3mm gave me ~25fps gain. 6mm lost me 30 fps. Gas rams don't like too much preload, plus shimming decreases the overall volume of cubic air being compressed. It's a balance between pressure & volume & for this rifle, 3mm was best.
Ya I would start with things you can reverse. Porting is permanent.
He’s a real dr. Suse. !
College boy . Need to work fer a ketchup company and design a new bottle that don’t squirt ketchup all over my dam clothes !!!
By the way ; don’t reinvent the dam wheel. The old bottle with a dam hole in the end works perfectly fine .
I know I’m off the subject; however it makes me feel so much better I I’m sure I’m not the only one . Can I get a a” man and a couple likes .
lol love it
was the hole round before you enlarged it, I thought that the barrel side of the hole was supposed to be square. let me know because I might try this myself. cheers.
It was round on my rifle.
did you try drilling holes in the piston to make it lighter
The piston compresses air so drilling holes in the piston would render the air rifle useless.
600 fps for a 177. Is really slow
Yes I agree but I like it quiet and there isn’t a ridiculous recoil
Im glad i noticed your video.
Thanks , i like and subscribe
Thanks so much appreciate that
if your rifle is a .22 then drill out the transfer port no bigger than 4mm max a tapered drill hole from the inside of the air cylinder is far better than a Strate hole drilled from the outside, but any drill hole made must be smoothed bored. no ruff edge's in the hole, as they will cause turbulence and slow down the passage of compressed air, deburr all the edges. you will need a stronger faster spring, but do not overload the trigger sear, or the gun will become unsafe and will start discharging without warning, if this dose not give you enough power all you can do now is bore out the air cylinder and change the piston size for a bigger bore, so you get more air capacity out the cylinder, to improve FT,PS = more FT,LBS more air in needed to push the pellet, but not that much more presser,
enlargin port is on air guns that were poorly made ,, so it will not give you even as much speed boost as lubing the cylinder on 50 shoots or so //spring and piston seal change is only way to get more power that is noticeable //no chronny I mean it can brake glass bottle on 40 yards that could pre fix brake it on 20 yards tops// get a diana 450 magnum if 177 //and you got most that 177 can do //and you will grow some muscle cockin it //and 22 cal is I think called diana magnum 460 //and is a pinch stronger than 177 //not a lot but if into hunting crows,rabbits , etc it is close to 1000 or more dollar prefilled air rifle //but there you got to fill bottle , shoots are not consistent ,, and power is at maximum 1/3 stronger with using slugs that cost at least 10 time vs top pellets
Nice idea thanks dude...fr.philipines
No problem friend
By opening the cylinder this will cause it to loose fps , what some tuners do is to drill it out the cylinder much wider and sweat in a piece of metal or brass and drill it out small then the original hole .Nice video Cheers 🍻
I was thinking of it as in an engine where you port it go get a larger volume of air to pass through. The reason I thought this was the way to go it that the piston will compress to a certain degree then slow down because it can’t over power the compressed air with the small hole restricting flow. So I figured if I bore it out a bit it would allow more air at the same pressure behind the pellet causing it to push it a bit faster before it because the barrel releasing the pressure.
@BROTUNED I can see your thinking , example a lot of owners in the past were told to drill out the cylinder because their was a restriction build into to it , so by drilling it out , this would give the rifle more power out put , but in-fact it ruined the cylinder and many had to purchase new cylinders . So wider reducers power small producers more power . Cheers 🍻
couple issues here:
increasing the "transfer port" diameter will NOT produce a higher velocity of air...it will ONLY increase the volume of air. So you have it backwards. If the goal is to create more pressure = a faster feet per second, then you would want a smaller diameter transfer port. but there are other physics that will control the actual maximum pressure. Most of this is due to variables that are not related to the size of the transfer port and have more to do with spring RATE and throw...as well as the size and fit of the pellet in the breech as well as the breech seal
second, I noticed you did not actually duplicate the same conditions in the before and after chrony. Are they set at the same distance? in the same barometric pressure (one looks like inside in warm controlled environment with chrony set up near the clay target and the other right near the muzzle in very cold weather. yes these factors make a difference in feet per second measurements. Also, are you using the same exact pellet brand AND BATCH?
another way to increase feet per second is to polish the inner charging barrel with "chrome polishing compound (never sand paper...that's just stupid!). the smoothness of the inner charging barrel will have less surface friction and the piston gasket can then accelerate with less resistance...producing a faster rate of pressure increase.....
another way to increase feet per second is to change out the charging piston gasket/seal....there are some aftermarket designs that have better materials and fitment that allow the charging piston to travel faster (less resistance) and still maintain a very good seal.
one way to deliver a faster feet per second is to simply use a lighter grain pellet weight. And there would be no need to make these kinds of modifications. Another way without modifying the "iron" is to simply upgrade the charging piston....swapping a springer to a nitrogen gas piston is probably the easiest and most reliable upgrade you can make to a standard springer to get a faster feet per second. And generally speaking, a nitrogen gas piston over a standard springer setup is going to get you less "noise" in terms of vibrations that affect accuracy.. gas pistons also generally do not have the loud "ring" that the standard springers do.
speaking of pellets...almost all pellets vary in actual gauge size...And this matters quite a bit in terms of speed, accuracy and consistency. For instance, I have a benjamin trail np xl (.177/4,5 mm) that will shot tacks every day as long as I use a H&N 4.51 mm pellets...read it again..this is a pellet made by H&N that is slightly larger in diameter...4.51 mm...So it's a tighter fit. I've demonstrated in chrony, it is a faster and more accurate pellet than any other in the same 10.5 grain size. So size matters if you are after accuracy and consistent speed....conversely, I have never been able to shoot accurately with "vortex" branded pellets or rws ...they have a very loose fit. and they fly all over the paper and record quite fps spread....the crosman domed premieres do okay...but it is the 4.51 mm H&N's that are the cats pajamas.
You forget, the piston will move faster with a larger port.
Hi gentlemen I have a Canadian Benjamin Classic .22 with a 3.80mm hole because of you now at more or less 510 fpi thanks next mod Titan XS Springs..! keep up the good work and let us know thank you.
Glad you enjoyed the video! Spring upgrade will make the biggest difference for sure
@@BROTUNED a small question what do you think of the Titan XS Springs !!! thank you.
Honestly I have never tested any so I can’t answer your question. I have tried a few different springs from vortekproducts.com and everything went very smoothly.
@@BROTUNED Ok thank you I will see for myself ..!
I have a Crosman Optimus .177 495fps, what kind of spring would I need for more fps? Not sure what I’m looking for online. Thanks.
650 fps ! Oh No, now you got a firearm.
Swat will be kicking down your door in Canada.
Even a Walmart blow gun is illegal there.
Go figure eh !
Incriminating himself
I dont think it gained that much cause in the video the first test was indoors with less air volume than the ice cold air outside we all know the colder the air is inside the chamer the more power...i did port my gamo vipermax and saw little to no difference
Never considered that
hello guys, how can I modify more power for one Weihrauch HW98 S - .22
Hello there my friend from Greece! It seems that only one person here in the chat section noticed it. You didn't show us the starting spread but after the mod you had an extreme spread of 46 fps between 672fps to 718 as we saw! This is a very different number than the manufacturers give us between 15-29 fps. You gained a bit of power but if you do some target shooting now, will be like firing a shotgun with round balls to your target! :)
It ended up settling down not sure why the es was so large
@@BROTUNEDDid it settle down , after how many shots? Maybe after the swarves have gotten themselves out of the chamber slowly? What fps spread do you have now?
It can take quit some shots before all oil residues have dieseled away. I noticed the same when working on my PCP's, a lot more spread on the first 10 shots, after that the rifle settles down and becomes more constant.
Good job. Thanks
Ya I wasn’t sure what would happen but there was a positive increase in velocity so I’ll take that as a plus. And for free
Do you think if you went a step bigger you would get more fps?
I don’t know for sure but in theory the more air pressure and volume you can get through the port the faster the pellet will leave the barrel.
That's cool it works
You bet it does. Ha ha anyways thanks and try it yourself!
I take accuracy over speed anyday
Pretty sweet
Thanks
I am from india...gud job bro...
Thanks very much
The best way to get more power is a better SPRING ..
Agreed
Drill it barrel enough for bullet and fit pin haha enjoy
How old is this tin of pellet ? Mines are marked 7.9gr!
I am surprised it increased the velocity the port looked already pretty big !
(or all the pictures are after the drilling?)
I think I couldnt even get a toothpick in a Gamo port so im starting to believe this may be the only thing detuning them
I dont think Crosman is using different port size for both versions tho !
Ya all pics are after the port job I forgot to get a baseline measurement
The pellets are about 10 years old ha ha
@@BROTUNED thats what I thought the port looks huge on all the pics 😁
I’m looking for a spring upgrade for my Crosman Optimus .177 495fps. What kind of spring do I need to get for more fps? I have no idea what I’m looking for online. Is there a certain size or length I need? Any help would be appreciated and great video.👍🏼
I get mine from vortekproducts.com I can tell you the exact spring I got but basically what I did was pulled the stock spring out and measured it’s length and wire thickness and added a few coils to it. Then I fit it in the air gun and if it got spring bind before it was cocked I would disassemble it again and cut a coil off of the spring until I had the longest spring that would fit without binding up and that’s about it.
@@BROTUNED That seems like a lot of work that I’m too lazy to do🤣 Would stretching my stock spring do the trick?
It may but I think that would be difficult To accomplish. You could add washers behind the spring to preload it and that would be a lot easier
I bought a brand new spring for the Crosman Optimus a few years ago from Canada Shooting Supply - it is the high power 1200fps spring and it comes with brand new piston and seal - I originally bought it to swap out the weak spring in my 495fps Crosman Phantom but never ever got around to doing it.
I cant tell you the exact specs of the spring off hand.. but it was cheap to buy and a better option than trying to stretch out your original spring.
Check Canada Shooting Supply and see if they still have them in stock.
@@dreadnaughttactical thanks man
The fps was vastly inconsistent with each pellet.
Ya I know not up to my standards so I went back to a lighter spring to get things consistent again
More power isn't always better, probably gonna kick more with extra power.
Ya lost accuracy big time and went back to around 650 fps and almost thinking of dropping it back to around 500. Makes it a lot easier to shoot well and if it’s for critters that will have no issue taking care of them.
@BROTUNED Yeah it's all about finding the balance with springers, some guns that tune really well it's possible to get a bit more power and a smoother shot cycle but would take a fair bit of polishing up.
I really wanna start using pcp’s but the start up cost is basically a voodoo rifle
@BROTUNED It is expensive but I'm not a big fan of pcps, they just feel dead to me, higher powered ones are gonna have a bit of kick though. I just love spring guns.
I’ve never tried a pcp but they look like they are very accurate
Was it at 495 fps when it was bought brand new?
Yes that’s basically what you can get in Canada. If an air rifle is over 500 fps you need a firearms license in Canada
Hi, I have a gamo magnum 1250 4.5mm and it's tube hole is 4 mm is it right to make it 4.5mm to gain more fps ?
That’s what I tried because that would be a restriction in the system. So I matched opened it up a bit and it did make a small increase of velocity.
@@BROTUNED many people say that if you have an air rifle 4.5mm the maximum opening in a tube hole is 3.8mm. I drilled it to 4.5mm and I do not know if it gets more fps or lose fps
Have you chronographed it before and after?
As you can see in the video I gained a bit wasn’t much but it did make a difference
@@BROTUNED nope, I used the pages of the same book as an example. I think that my pellet penetrated a few more pages.
I would be concerned with piston slam, my question is what does it shoot like now, does it have more recoil, is it accurate.
It has more recoil and I’m probably going to go down a bit on the spring.
So I'm wondering if you paint an air rifle with a rubberized coating if it will deaden piston slap.
Ive read a lot of people saying that porting can ruin many rifles but I've wondered about polishing and beveling the port for less angle of extry.
Not to sure. Maybe a rubber bumper for the piston to hit would work
@@BROTUNED yeah like a cut dowm poly bush! Thats not a bad idea...
I increase my port size by 0.5mm Didn't make any difference at all to fps or ft/lbs.
Maybe the Canadian models are more restrictive
I have a gamo varmint 495 any way to increase fps
Get a new spring for it.
The air rifle companies have maximized the blow through holes on the piston chamber sides. My advice would be get a more powerful air rifle,rebuild the piston, or upgrade the model with performance parts where applicable! Ruining the air rifle proves nothing but ignorance. You can always upgrade to an Pcp air rifle for superior performance.
I’ve been looking at pcp’s for a while now but start up cost is more than a custom 22
@@BROTUNED Those extra costs are only once. You can keep the pump/bottle/optics when you upgrade or buy another pcp.
Ya I know I really want one just need to do more research
Sorry. Which Airgun is this?
This is a ruger air hawk .177
I tuned my webly falcon spring gun up ox spring drilled out the air release hole slightly bigger washers behind the spring got stopped by police out shooting rabbits thay tested my gun it was 16 ftpound the leagle limit in Britain is 12 I was arrested gun conferscated I had no idea of the laws bk then they set anything over 12 u need a fire arm certificate
Omg that’s no good
They tested it right there on the spot then arrested you ? 🤔
Drilling a transfer port on an airgun is probably the worst idea of all.
Think of it as a blowpipe, you want the maximum of air passing very quickly trough the smalest hole possible.
Or try to think of what your mouth does when you spit far, now imagine spitting with your mouth fully opened...see where I'm going ?
Most guns already have the transfer port maximised, tho you may gain some fps if lucky, you have more chances of ruining the gun or making it shoot LESS fast...
Believe me I tried 🤦🤦🤦 fawk me
I understand what you’re saying but it’s cheap gun and I’m experimenting with it . Not to worried about it but it does shoot better now. I think I’m going to put a lighter weight spring back in it though the recoil is getting ridiculous the heavier I go.
@@BROTUNED
If you want to open the port they do not recommend going higher than 80% of the pellet squirt diameter. Under that is OK I guess ... 🤷
I know what you mean about the crazy recoil.
All the guns I buy are under 500fps without a licence (heh Canada), tho they do shoot very smoothly right out of the box, then I try my best to bring them as close as I can to the legal capacity.
Most of the time I just end-up with a gun that's too powerfull to stay legal with an unpleasant "boïoïoïong" effect. The fix to that is to fit a gas ram instead of a spring.
The best way to gain a lot of power (you have already done) is to plug the hole in the piston. You get on average 200 more fps.
Also you can literally bathe the spring in grease, polish the piston with a very fine sandpaper and lightly grease it also. Check if the chamber is free of sand or other particles. You can gain an additionnal 30-60 fps just by eliminating metal friction.
✌
Nooo that ruinsaccurasy onooooo..
Put some diesil in the back of the pellet. Compressed air will ignite it.
Regular oil also but so inconsistent
@@BROTUNED Try a mix of vasaline and diesil.. I've not tried yet but sounds about right don't it..
How fast will it go????
@@BROTUNED apparently I've seen vids saying it will increase from 800 fps to 1000+ fps.. I'll do it after the festive season, when I'm not drunk anymore.
Lol that’s awesome! Cheers 🍻