Wow…. I built an ar9 over the winter. I was shocked at the amount of recoil. My fingers actually went numb from shooting it. I found this guy and ordered the goodies he mentioned in the video and is page. Well worth the money. Almost no felt recoil now. Follow up shots are easy. If you are on the fence… do it. I know it’s not cheap… but it’s worth it.
Ditto! My EPC9 wasn't horrible on recoil, but it did start to make a sore spot on my shoulder. It's a little kitten now. Stoked you had good results too!
This man is a legend .. it’s like seeing a real artist release a song, after seeing a watered down genre of music . This is gun enthusiasm. trial and error and the perfection of a craft . Passing knowledge.
I honestly can say that without this guidance my ar9 would be in a dumpster. It now runs almost perfectly with much of the "snappiness" gone. Thanks, Blowback9!
I was looking for a solution to the heavy recoil on my 9mm PCC and the annoying spring sound in the buffer tube. I bought the parts he recommended and IT WORKS! The recoil is greatly reduced and the flat spring eliminates the spring sound in the buffer tube. I would say the recoil is on par with the roller delay system on my MP5. Thank you Blowback9 for the research on reducing recoil on the AR9.
I want to thank you for all the research and real world experience you bring to this topic. Your gentle recoil system really tamed my recent SBR build!
Wanted to send you a message and let you know that I bought the exact parts you suggested and put everything together on my EPC9 upper with 80 Percent Arms AR9 lower and it worked flawlessly!! The snappy recoil into my shoulder was at least half if not better and I was able to stay on target and shoot more comfortably. Amazing work and experimentation and tutorials explaining how to put this together. I am amazed and at much recoil is just...gone. You are a gentleman and a scholar and you have a lifetime subscriber and advocate. For anyone wondering if this will work, just by the parts and put it together and go shoot it. I'd highly recommend either shooting your old setup first and then doing the swap and then going out and testing it or doing a side by side with a "regular" AR9. Take video if possible. I have a Witt Machine 9mm suppressor awaiting a tax stamp. I'm very excited to try this setup out with the suppressor and see how that goes. Again, thank you, thank you, thank you! 😁
Just subscribed after watching one video. Great, practical, "regular guy" tone but far more than regular insight and info. Gotta go binge your playlist, into the rabbit hole I go.
I bought a Frontier Arms 9MM AR pistol with a 8inch barrel from AIM Surplus because it was on sale for $250 off at the time. Before I even tried it I used the money I saved to get a Blitzkrieg hydraulic buffer and a flat wound carbine spring. It has been 100% reliable and even without the added weights, recoil is not bad at all. I would not be surprised if all the shooting I do with WWII surplus rifles in .30-06, 8mm, 7.62x54 and 7.5 Swiss makes everything else seem tame by comparison.
I never felt my AR9 recoil was bad but I have an Odinworks adjustable weight PCC buffer with all the tungsten (I think around 9oz), a Law Tactical folder and a Toolcraft BCG with the weight insert shortened to fit the carrier plug from the folder. It's as much carrier/buffer weight as I could get without adding weight outside the buffer. It fits in a standard carbine buffer tube with a standard spring (not flat wire). After I put it together I noticed people complaining about AR9 recoil but I wondered what they were talking about. Also I used a modified carbine stock stopper from Strike Industries to limit my adjustment range. At the shortest it stops before the buffer tube pokes out of the back and at the longest it is less than the ATF's old limit for pistol brace LOP before they decided to ban pistol braces. Luckily they have been injoined from enforcing their new rule on me because I'm a member of a group suing them who recieved an injunction before the rule went in to effect and I'm covered by that and the nationwide injunction now. I don't have a hydraulic buffer but i don't think I need one, it's very soft shooting and controllable with a 7" barrel and plain muzzle. It's not terribly heavy but the mass of the gun probably helps. It has the brace, the folder adds some weight, it has a Trijicon MRO and a pistol length Mlok rail with a UTG AFG. That's not too heavy and the rest is pretty standard stuff, nothing excessively heavy or specifically light weight. It's still quite heavy compared to a Glock 17. I broke it in doing the PCC class of a competition. Bottom line, it just ran and it was really easy to shoot fast and accurately (compared to how slow I normally shoot). I typically shoot CCI Blazer Brass at the range because it seems pretty consistent and the brass case treats the action better than steel. I don't know what it would feel like with +p or +p+ type ammo but the 7" barrel pretty much maximizes muzzle velocity so standard ammo is probably moving as fast as +p ammo shot from a 4" barrel.
Draco 9s with brace is a flat shooter and repeat shot low recoil carbine. Its amazing. That being said my shorty ar9 is spot on for a single shot, but jumps around like crazy if I do double taps or fast shooting
Thank you for the very much for the simple video and link to your research. I will be trying out the hydraulic buffer and Tubb flat wire spring in my Colt 9mm. After trying it out, i might continue and get the longer tube and spacer weights to complete the gentle system
For an EPC 9 build (carbine buffer tube) I bought the Kynshot 5015 & flat wire spring, but did NOT buy a spacer weight. Will I still be good to do or do I NEED to buy the weight?
As you know I did a vid on it, and I am loving it. I might try out a flatwire spring to see if you're right about noticing the noise subconsciously. Thanks again for your work, you are doing a great service for the gun community.
@@jacobcarter6028 um, it’s over a month late but I emailed support and a guy called my cell phone and said he’d throw in a t shirt whenever it gets shipped Lame af lol. Gonna ask for a discount on a 10mm dissent
I have the Maxim RDB and its awesome but man it is hard to overcome the ball bearings, I haven't had it long and only have 570 rounds through it and its gotten easier but still shockingly difficult.
I saw this video after I purchased the Kynshot plus Springco Orange spring, so that's what I am going with to start. Did not realize the HD version has DOUBLE the resistance. I am not sure if that's good or bad. That sounds like a lot with the two weights. One thing about a 16" barrel; I started with a pistol build and went to a full stock 16". I think the added weight eclipses any additional felt recoil. Also, a 16" barrel 9mm is rather quiet. If this does not work out I actually have a Just Right buffer sitting around and an extra M4 spring, so I could try with the two spacers. Oh - about Botach. Yes they are less. I ordered from them, they sent me a shipping notice, then, they cancelled the shipping notice and said it would be three weeks on back-order!! So I ended up getting the standard Kynshot from Brownells. Will post more info when I get to the range and try it out.
If you swap that orange for a normal carbine (or better yet, a flatwire carbine to get rid of the spring noise) spring you'll likely notice a big difference in how it feels and functions. Have fun, be safe!
@@Blowback9 Ahh! I took the time to read your analysis of the 308 spring (and presumably Orange springs, etc). Great write up. [EDIT] Oops - meant to put this reply where you reference 308 spring write-up.
WOW, thank you this is the most impressive recoil reduction system yet! It makes my Foxtrot Mike 9mm shoot like a totally different gun and shoots way smother & flatter that before!👍
FYI per Kynshot if you use a A5 length buffer tube (8" OAL / 7.75" internal depth) you should pair the Kynshot buffer with ONE spacer. If you get the buffer tube mentioned in this video that is 8.5 internal depth is why he mentions 2 spacers. A5 Tube = Kynshot 5007, 1 Kynshot spacer, Flat Carbine spring.
Unfortunately I don't know of any pistol tubes that are 8.5" internally, but there is a configuration that will fit in a normal carbine/pistol tube and provide most of the recoil benefit: blowback9.wordpress.com/2023/05/28/9mm-ar-gentle-recoil-buffer-system-final/
I read in your docs that you used the Kynshot R5000HP hydraulic buffer with a 3.25" length. Why did you use that with the JRC long buffer tube and not the Kynshot RB5015HD with a 3.9 length? Kynshot says that one is designed for PCC's. I've never used any kind of hydraulic buffer, Kynshot, or anything else. I might try this so I'm curious as to why you went the way you did.
On my site there are additional configurations for "gentle" recoil, and each group of parts - tube, weights, and buffer - is very specific and can't be mixed/matched. Together they give the right travel and spacing for the 9mm bolt in the receiver, otherwise damage could occur. The 4" is considered "PCC" because it's too heavy for 5.56 and the length is correct for the generic typical configuration of a 9mm bolt with a carbine tube. The 5000HP measured as about the same piston compressive force as the 5015HD, it's just a little shorter and lighter. Adding a spacer weight in front gives it 4" total (PCC length) and is slightly heavier than the 5015HD, giving a slight mass advantage. Hope that helps!
Yes! I've always takes umbrage with the springy twang of the M16. I liken it to an old screen door with a simple spring closing mechanism. Anyone that I ever described it to - even having just fired a round - they tend to not know what I am talking about. I find it very distracting. And it makes me feel like the rifle is lower quality than it should feel. Like a toy that could kill you. And that's a bad feeling to have.
Man your videos and research are second to none! I truly appreciate your videos and shared knowledge!!! That said, I have a question, Will the kynshot competition short stroke 7.7 oz buffer work the same in an 8” A5 buffer tube without the added spacer weights? I’m building an aero epc9 with the b. King 9mm bolt.
I haven't played with their competition buffer yet, but as long as the bolt travel distance is right, it should work. I check for proper travel distance by making sure the bolt face stops about 1/8" to 1/4" behind the bolt catch when the CH is pulled all the way back (and the piston is compressed).
Just an update, the competition short stroke ran flawlessly in the 8” A5 tube. Bout 200 rounds through it and no malfunctions or failures to feed with 27rnd pmags. Feels smooth as butter!
The tube length is critical for getting the correct bolt travel with all the additional spacers. Check here for the tube/parts combos that work: blowback9.wordpress.com/2023/05/28/9mm-ar-gentle-recoil-buffer-system-final/
I recently bought the Palmetto State Armory PX9 Gen-4 rifle. WOW the amount of crud that is blown into the receiver and out the ejection port! My brother is left handed and can even see the amount of powder residue being blasted on his face! The brass casings are even ridiculously covered with crud and quickly turned the costly walnut media in my tumbler into looking like I am tumbling with charcoal. I' m now seeing these exact same complaint from even years ago, and so it's pathetic that any company would still be letting their guns leave the factory with their schitty light weight buffer. Theyre charging an average of 800.00 for the gun and yet theyre then making us pay for the PROPER 8oz buffer which significantly helps keep the bolt closed longer in order to keep most of the crud in the chamber and it reduces the recoil
Just another observation; there seems to be a lot of debate as to whether to go with more weight and a standard M4 spring or more spring tension (308 or similar) and less weight, or a balance of both.
Yes, there's a lot of debate, now that the myth that a .308 spring is somehow beneficial for 9mm has been challenged and shown to be without merit. No one has ever provided any empirical evidence that .308 springs are either necessary or beneficial. Instead, the've been connected to many significant problems with the platform that are resolved by switching back to regular strength springs. More info and analysis: blowback9.wordpress.com/2021/04/07/the-case-against-308-rifle-recoil-springs-in-a-9mm-ar/
Theoretically, could one use the KynShot shorty .308 hydraulic buffer RB5004 (2.5" long and 3.8oz), with 2 of the 2.5oz, .75" long spacers, in a standard length carbine tube, totalling 8.8oz in the tube? Weight would be down by 2.2oz under your setup in this video @ 11oz but you keep the shorter tube. I suppose one would have to experiment in their combo. I run an 8oz buffer in my 16" home build, and feel it is not under weighted, atleast not severely anyway, and that is just a standard buffer without the hydraulic dampening effect.
I digress, I am running the 11oz AR Stoner extended (blue) buffer in my home build. It is 4" long exactly. Damn, the extended buffer tube looks to be the way to go.
Have you tried the JP silent capture 9mm setup? Wondering what you thought. I just don’t like the thought of a hydraulic buffer, seems like a high potential for failure
Keep in mind your length of pull folks.(ie ar-pistols) The three letter bois are always looking for a new canine to shoot. If you dont know about lenght of pull you need to research.
I can't find "length of pull" anywhere in the NFA or GCA as passed by congress. SCOTUS recently killed Chevron deference. Food for thought. I am not a lawyer, this is not legal advice.
Hi, I went to Botach website and the description for the 9mm buffer (RB5015HD) says it’s for use in 8” barrels or greater. I’m running a 7” barrel. Have you tested this system with barrels shorter than 8”? Thanks.
Have you tried or heard from anyone who has tried using this system with a PSA AR-V? I didn't see any mention of it on your website, but I imagine it wouldn'thave any issue. I find the Scorpion/U9 mags to be the most aesthetically pleasing as well as being cheap, available, high capacity, and reliable to my knowledge, so it was high on my list for AR9 candidates.
Fantastic video, I wish I had seen this sooner! Is the Spikes 9mm bolt good for an EPC9 upper build, or should one use one of the bolts on your website?
Thank you for sharing all your research. Being from NJ I will have a 16" barrel on my 9mm AR. Im definitely going to buy this buffer system but do you have a recommendation on BCG?
Ever used the kaw valley pcc spring? I have one with a vltor stainless buffer, haven't used since I still need a handguard for it, just curious if you've tried a similar combo yet
No. XP springs are not necessary or beneficial for 9mm. They can cause a bunch of problems, instead. More here if interested: blowback9.wordpress.com/2021/04/07/the-case-against-308-rifle-recoil-springs-in-a-9mm-ar/
@@Blowback9 I did not realize that it's just a 308 spring, sob. Well the lower that I plan on using has a strike flat wire so I'll just swap the buffers when I need to and keep the other spring for whenever I get around to an ar10 build
I’ve got a JP GMR15 with a Aero Precision buffer tube. It is 7.25” in length. I’m looking on your site at the recommendations and I’m not sure which to go with the Kynshot RB5000 or the RB5015HD. Ordering the Tubbs flat wire for it but I need help on which buffer to choose thanks.
I have an Aero Precision carbine buffer tube sitting beside me - it's 7" internal, the same as a standard carbine tube. Don't count the long "tongue" sticking out the bottom open end. Measure at the top.
Ordered the Kyn-Shot Rb5000hp and Kynshot spacer with the Tubbs flat wire from the link on your site. Can’t wait to test it out!! I’m thinking about putting a Devil Dog Side charger on it too, have you used one of those?
Would you recommend this setup for a 5.5” barrel with a 4 inch suppressor and a law tactical folder? I know you mentioned getting as much weight as possible with suppressors and wanted to confirm with you. Thank you!
First off thanks for sharing all of your information and thoughts about AR-9 mechanics/physics. Question for the blow back recoil system improvement on this platform: would inserting a 24mm - 25mm diameter 5mm - 10mm thick rubber washer/gasket pad with a hole in the center the same size as the end of the buffer tube at the rear help reducing felt recoil? what are your thoughts seems to me that could help reduce/absorb some felt recoil but I'm not sure how negligible the improvement might be.
Sounds like the Tacticool buffer for the Sub-2000 - check it out. It should have an effect on the felt impact of the buffer. The hydraulic buffer piston essentially serves the same purpose in the gentle recoil system.
testing it out tomorrow, thanks for posting all this. I looked but didn’t find any discussion on barrel length running this system, does barre length not really matter? I have a 8” for tomorrows range day but thinking about swapping to a 5”.
testing it out tomorrow, thanks for posting all this. I looked but didn’t find any discussion on barrel length running this system, does barre length not really matter? I have a 8” for tomorrows range day but thinking about swapping to a 5”.
man i wish i had seen this 6 months ago. Im now wayyy to deep "additively" building a mp5 with an ar lower. however, matador makes an all-in-one upper that had my eye as well. v I wonder if they did anything to resolve the recoil or not.
How would you retain the recoil characteristics of this system while incorporating a LAW tactical folding system? My initial thoughts are to weigh the LAW plug and just cut enough of the weight from the bolt needed for the plug to insert and then reinstall it, comparing the amount cut from the weight to the weight of the plug to see what the difference is. Has anyone does this while using this "Gentle recoil system"?
With most bolts, the cylindrical internal weight is 2.5oz. My Law plug is about 2.2oz., so the weight difference is minimal. The GRS works fine with my Law system build.
I was wondering if you could help me with feeding issues....i just finished my build and used your grs with all the parts listed on your website. I have an 80% glock lower with a gibbz arms side charging upper, and a faxon bcg and faxon 8.3in barrel.Just tried it out for the first time and with only putting 2-3 rounds in the magazine at a time, the bolt would not seat all the way. Any recommendations?
I have exactly the same Hydraulic Buffer and long flat wire spring plus one of the 3/4” 2.5oz spacer weight in my S & W Response with the factory 7.25 or 7.3” buffer tube. Big improvement in felt recoil. I tried adding a second 3/4” 2.5 oz spacer weight but that didn’t allow enough room for the bolt to lock open. I’m wondering if I will be able to tell the difference if I install the 8.5” buffer tube with the 2nd 2.5oz spacer weight… Ummm
Is there a buffer tube "recoil buffer" similar to the ones that Mcarbo, Missouri tactical, and tacticool products offers for the Sub 2000? I think extar uses a somewhat similar "system" in thier buffer tube as well. Do you think this would reduce ar9 perceived recoil?
You mean a neoprene-type squishy thing? Not that I know of, but that was my inspiration for using a hydraulic buffer. I had a tacticool buffer long ago in a keltec sub-9 (pre-sub2000).
@blowback9 Have you tested the CMMG delayed recoil system combined with your gentle recoil system? Really interested to hear what you think of the combination CMMG uses their system in the Resolute 9mm model and full buffer tube.
How does this compare to the scheel roller delayed buffer? Or to the combo that max Leograndis used to use? (Rb5020ss, springco orange, a5 tube, short stroking spacers)
Softer and slower than the scheel. The scheel can tuned for better dot movement but this is much better across more ammo types. The max combo is great for soft reloads but has more felt recoil and is snappier/ faster for sure.
I try to. You don't need an 8.5" tube unless you're trying to make the Gentle Recoil System. A regular carbine tube, 11oz. buffer and flat carbine spring will work just fine.
Hey so which setup would you recommend for a competition PCC with 10-12 inch barrel length? I want to go with as fast double taps as possible, preferably with lowest possible recoil.
I don't do competitions, but my understanding is that the lighter setups are better for reducing dot jiggle even though they produce greater felt recoil. I'd try the lightest buffer setup that's appropriate for the bolt's mass (bolt+buffer total around 22oz.)
@@Blowback9 I've got all my parts! 3 weights plus all the rest definitely added a nice bit of heft, I'm here to thank you again for being such a resource. Reason being, I haven't had the chance to take it to the range, but manually operating the action has my ejector barely flopping them out but usually failing. Saw the page on this issue and I'm going to be able to easily fix it because of you
@@Blowback9 So I'm unfortunately using an Aero EPC9 lower and the extractor can't really be bent, do you happen to know anything more about this lower? I probably should have taken it out to the range before trying to troubleshoot ejection, it just doesn't eject if I manually operate things.
I’m back with my results now that I’ve built a GRS in my 7” FM9 and tested it out. I went with: 1) VLTOR tube 2) Kynshot RB5000HP 4.8oz 3) 2 weights totaling 5oz 4) WC flat wire spring Does it work? Absolutely. Is it worth $196? Not even close. But that’s okay. I enjoyed the process and it’s still 1 of my most favorite ARs to shoot. I still plan on making additional modifications. The stock FM bolt is 14oz. I’m going to upgrade to a 16oz eventually. I see Faxon has a 16oz bolt. Any recommendations on it or something different? Thanks again for all your testing. It’s a wealth of information.
Although it wasn’t worth the money to you, how was the overall performance of it your FM9 compared to stock? I recently got one and thinking about doing a similar recoil system in it.
It performs amazing. 2 weeks ago I got to shoot mine next to an identical stock version. It’s at least 15% softer. Half of that is due to the increased weight. I’m happy with the end results. If $ is no concern, I say go for it. If on a budget, I would focus on other things 1st.
@@scott2228 Great, thanks for the reply. I think I’m going to start with the kynshot buffer and a springco red carbine spring. I see another build that had that and it ran so smooth suppressed with just that. On a separate note, I’m curious to if your FM9 had any problems with feeding using full 33rd Glock mags. My mags work fine as I’ve only had them at 60% while im breaking it in but I put a few extra in one of them and it jammed second shot. If they are full the first round jams after dropping the bolt, seems like there’s too much pressure in the mag. And a few occasions my trigger didn’t reset when I first took it to the range but seemed fine as I shot my last few mags towards the 200 round mark. Did you ever experience this same issue?
Sounds like a good starting point. I never load past 30 rounds. Those last 3 rounds just seem silly to me. Every once in a while I’ll get a hang up on a full mag with the Kynshot. It’s never happened with regular buffer. Speaking of regular…. I got great results using FM’s 45ACP bolt and the SprinCo Red.
@@scott2228yeah I wouldn’t load them to 33 either. I load mine to 30 and it seems to be an issue loading the first round.. granted I hadn’t got past the break in point so idk. Figured the mags maybe need to loosen up a little bit. Are you saying you had occasional issues with the trigger resetting when using the kynshot?
If it hasnt been said or questioned down in the comments and or if you have explored this type of setup. Your setup; weights, buffer and all, with a Geissele super 42 spring and a law tactical folder, your input/2 cents/ opinion? When i installed the law tact folder on my ar15, I needed a stronger spring, hence the geissele, to reliably feed. Looking forward to building a more serious PCC. Thanks, good stuff you got!
Oops. I had the weights in the tube first, then spring and finally buffer. It still worked but I moved the weights behind the buffer now. Does it made a difference?
Is the 5015hd the same length as the 5007? I went to order the 5000hd but out of stock so got the 5007 pairing with the 8.5 tube and 2 spacer weights. Will this configuration work for a 16" barrell?
How would this compare to the Maxim Defense roller delay buffer? Also, what length spacer would you need in the rear for an A1/A2 buffer tube? My current setup is a 16" Foxtrot Mike FM9 with a Doublestar ACE ARFX 10" fixed stock, and i used a spacer from MidwayUSA to make it carbine length internally for the Maxim RDB. I also had to remove 0.084" (iirc) from the spacer for the RDB to fit properly. I currently have 570rds through it with 0 malfunctions (all S&B 115gr fmj) and recoil isnt bad at all. The thing that i don't like about the RDB however is how hard it is to overcome the ball bearings when pulling the charging handle back. After 570 rounds it has gotten noticeably easier, but is still pretty difficult, and I'm a pretty stout guy. Everyone ive showed it to thought it was seized until i said jerk hard and they got it. Im thinking of building another but regular blowback (i went with the RDB for weight savings). Oh also i removed the added weight from the bolt for clearance with the RDB. Any ideas? Thanks!
If the new post May 2024 Wilson Combat Flat wire spring no longer fits the Kynshot, what buffer spring do you recommend as an alternative that will work?
Will this setup work on a typical AR15? Im trying to make a flat shooting laser pointer. Do I need to purchase the 8.5 inch long buffer tube plus the correct hydraulic buffer plus the kynshot spacer weights if I wanted to run the same recoil dampening benefits on an ar15?
I would use an RB5000HP buffer and 1 spacer weight with a carbine tube to get some improvement over a standard buffer setup. For a larger improvement, I'd swap to an A5 tube and use 2 spacer weights (with the same buffer).
I never specifically compared grain weight, but 147 seems to produce less rearward force. In my Overmass Project, 115 would cycle when 147 might not, so it appears the 147 was producing less blowback energy.
I wanna see you succeed my man.
Thank you! I had to step away for a bit and missed this, but I'm back! Lots of new content coming soon.
Hell yeah. Reno is in here.
We need you to succeed Reno. With your case as well as in life.
This man’s research and development of a soft shooting 9mm AR setup is greatly underestimated. Bravo sir. I’m here because of your Reddit fame! ✌🏼
Wow…. I built an ar9 over the winter. I was shocked at the amount of recoil. My fingers actually went numb from shooting it. I found this guy and ordered the goodies he mentioned in the video and is page. Well worth the money. Almost no felt recoil now. Follow up shots are easy. If you are on the fence… do it. I know it’s not cheap… but it’s worth it.
Ditto! My EPC9 wasn't horrible on recoil, but it did start to make a sore spot on my shoulder. It's a little kitten now. Stoked you had good results too!
This man is a legend .. it’s like seeing a real artist release a song, after seeing a watered down genre of music . This is gun enthusiasm. trial and error and the perfection of a craft . Passing knowledge.
I honestly can say that without this guidance my ar9 would be in a dumpster. It now runs almost perfectly with much of the "snappiness" gone. Thanks, Blowback9!
Glad I could help!
My Wife cheered in agreement @7:20 when you said: "...you need that extra inch and a half."!!!
LOL!
I was looking for a solution to the heavy recoil on my 9mm PCC and the annoying spring sound in the buffer tube. I bought the parts he recommended and IT WORKS! The recoil is greatly reduced and the flat spring eliminates the spring sound in the buffer tube. I would say the recoil is on par with the roller delay system on my MP5. Thank you Blowback9 for the research on reducing recoil on the AR9.
Nice! I'm glad you like it. Thanks for the feedback!
I cannot thank you enough!!! What a difference with your gentle recoil system. It went from so unpleasant to shoot to an absolute joy. Thank you
I want to thank you for all the research and real world experience you bring to this topic. Your gentle recoil system really tamed my recent SBR build!
Wanted to send you a message and let you know that I bought the exact parts you suggested and put everything together on my EPC9 upper with 80 Percent Arms AR9 lower and it worked flawlessly!! The snappy recoil into my shoulder was at least half if not better and I was able to stay on target and shoot more comfortably. Amazing work and experimentation and tutorials explaining how to put this together. I am amazed and at much recoil is just...gone. You are a gentleman and a scholar and you have a lifetime subscriber and advocate.
For anyone wondering if this will work, just by the parts and put it together and go shoot it. I'd highly recommend either shooting your old setup first and then doing the swap and then going out and testing it or doing a side by side with a "regular" AR9. Take video if possible.
I have a Witt Machine 9mm suppressor awaiting a tax stamp. I'm very excited to try this setup out with the suppressor and see how that goes. Again, thank you, thank you, thank you! 😁
Found your blog a couple years ago. I love what you're doing, such a great resource. Thank you for shaeing.
Just subscribed after watching one video. Great, practical, "regular guy" tone but far more than regular insight and info. Gotta go binge your playlist, into the rabbit hole I go.
Awesome, thank you!
I bought a Frontier Arms 9MM AR pistol with a 8inch barrel from AIM Surplus because it was on sale for $250 off at the time. Before I even tried it I used the money I saved to get a Blitzkrieg hydraulic buffer and a flat wound carbine spring. It has been 100% reliable and even without the added weights, recoil is not bad at all. I would not be surprised if all the shooting I do with WWII surplus rifles in .30-06, 8mm, 7.62x54 and 7.5 Swiss makes everything else seem tame by comparison.
Your website gave me all the info I needed for my AR9, been shooting it for a couple years now! Thanks!!
Great to hear - thanks!
I never felt my AR9 recoil was bad but I have an Odinworks adjustable weight PCC buffer with all the tungsten (I think around 9oz), a Law Tactical folder and a Toolcraft BCG with the weight insert shortened to fit the carrier plug from the folder. It's as much carrier/buffer weight as I could get without adding weight outside the buffer.
It fits in a standard carbine buffer tube with a standard spring (not flat wire).
After I put it together I noticed people complaining about AR9 recoil but I wondered what they were talking about.
Also I used a modified carbine stock stopper from Strike Industries to limit my adjustment range. At the shortest it stops before the buffer tube pokes out of the back and at the longest it is less than the ATF's old limit for pistol brace LOP before they decided to ban pistol braces. Luckily they have been injoined from enforcing their new rule on me because I'm a member of a group suing them who recieved an injunction before the rule went in to effect and I'm covered by that and the nationwide injunction now.
I don't have a hydraulic buffer but i don't think I need one, it's very soft shooting and controllable with a 7" barrel and plain muzzle.
It's not terribly heavy but the mass of the gun probably helps. It has the brace, the folder adds some weight, it has a Trijicon MRO and a pistol length Mlok rail with a UTG AFG. That's not too heavy and the rest is pretty standard stuff, nothing excessively heavy or specifically light weight. It's still quite heavy compared to a Glock 17.
I broke it in doing the PCC class of a competition. Bottom line, it just ran and it was really easy to shoot fast and accurately (compared to how slow I normally shoot). I typically shoot CCI Blazer Brass at the range because it seems pretty consistent and the brass case treats the action better than steel. I don't know what it would feel like with +p or +p+ type ammo but the 7" barrel pretty much maximizes muzzle velocity so standard ammo is probably moving as fast as +p ammo shot from a 4" barrel.
Draco 9s with brace is a flat shooter and repeat shot low recoil carbine. Its amazing.
That being said my shorty ar9 is spot on for a single shot, but jumps around like crazy if I do double taps or fast shooting
Thank you for the very much for the simple video and link to your research. I will be trying out the hydraulic buffer and Tubb flat wire spring in my Colt 9mm.
After trying it out, i might continue and get the longer tube and spacer weights to complete the gentle system
Let me know how it goes!
For an EPC 9 build (carbine buffer tube) I bought the Kynshot 5015 & flat wire spring, but did NOT buy a spacer weight. Will I still be good to do or do I NEED to buy the weight?
I just put a AT3 Muzzle brake on my build . Helped a lot so far i did one mag test at 100 grabbed a 1.5 group thats shootinthrough trees ..
This guys knows his shit... Just subscribed... Thanks for all of your research and testing...🇺🇸
As you know I did a vid on it, and I am loving it. I might try out a flatwire spring to see if you're right about noticing the noise subconsciously. Thanks again for your work, you are doing a great service for the gun community.
If you try a flatwire, let me know what you think! I won't go back to roundwires now.
im super hype to try it out and compare it to my maxim roller delay system when i finally get that delivered
How’d it do?
@@jacobcarter6028 um, it’s over a month late but I emailed support and a guy called my cell phone and said he’d throw in a t shirt whenever it gets shipped
Lame af lol. Gonna ask for a discount on a 10mm dissent
How was it?
How'd it go?
I have the Maxim RDB and its awesome but man it is hard to overcome the ball bearings, I haven't had it long and only have 570 rounds through it and its gotten easier but still shockingly difficult.
A sincere thank you for making these videos
I'm going to give this a try and come back with results.
Thank you for the research and development. You have 100% earned my subscription!
Awesome! Thank you!
Results? 🤷🏻
Is 9mm 7.5inch less loud than 5.56? I like how 7.5 inch ar 15 looks with pdw stock
Absolutely, 9mm is usually designed to burn all of its powder in a 3-5in barrel.
@@nnerrfman6326 thanks!
I saw this video after I purchased the Kynshot plus Springco Orange spring, so that's what I am going with to start. Did not realize the HD version has DOUBLE the resistance. I am not sure if that's good or bad. That sounds like a lot with the two weights. One thing about a 16" barrel; I started with a pistol build and went to a full stock 16". I think the added weight eclipses any additional felt recoil. Also, a 16" barrel 9mm is rather quiet. If this does not work out I actually have a Just Right buffer sitting around and an extra M4 spring, so I could try with the two spacers. Oh - about Botach. Yes they are less. I ordered from them, they sent me a shipping notice, then, they cancelled the shipping notice and said it would be three weeks on back-order!! So I ended up getting the standard Kynshot from Brownells. Will post more info when I get to the range and try it out.
If you swap that orange for a normal carbine (or better yet, a flatwire carbine to get rid of the spring noise) spring you'll likely notice a big difference in how it feels and functions. Have fun, be safe!
@@Blowback9 Thanks for all of the info.
@@Blowback9 Ahh! I took the time to read your analysis of the 308 spring (and presumably Orange springs, etc). Great write up. [EDIT] Oops - meant to put this reply where you reference 308 spring write-up.
No worries! Yes, "Orange" is what Sprinco calls their .308 carbine spring. @@calicojack556
When you buy a flat wire recoil spring they should automatically include one of those KAK recoil spring installation widgets with the spring!🙂
True! KAK does, and they also have a free .stl file for 3D printing you can download.
WOW, thank you this is the most impressive recoil reduction system yet! It makes my Foxtrot Mike 9mm shoot like a totally different gun and shoots way smother & flatter that before!👍
Glad to hear it!
I have a Foxtrot Mike 9mm. did you use the longer tube and two weights? thanks
I just received all the components you recommended and I’m excited to try it in a foxtrot mike’s that wld rattle, your fillings loose with recoil
I think you'll be happy with it!
Amazing research!!! Have you been able to test if the use of a suppressor changes reliability?
Thanks! Runs great with a suppressor.
Have you tried the buffer/bcg combo from JP Enterprises?
FYI per Kynshot if you use a A5 length buffer tube (8" OAL / 7.75" internal depth) you should pair the Kynshot buffer with ONE spacer. If you get the buffer tube mentioned in this video that is 8.5 internal depth is why he mentions 2 spacers.
A5 Tube = Kynshot 5007, 1 Kynshot spacer, Flat Carbine spring.
Would a 9'' tube with 2 spacers work or do you need 3? Just Rt. Carbines doesnt offer 8.5 only 9.
The JRC tube is 8.5" internal, which is the important measurement. 2 spacers with a 4" buffer.
Verified it works perfectly! Quick question I hope, are there any other pistol tubes that might work, instead of a carbine tube?
Unfortunately I don't know of any pistol tubes that are 8.5" internally, but there is a configuration that will fit in a normal carbine/pistol tube and provide most of the recoil benefit: blowback9.wordpress.com/2023/05/28/9mm-ar-gentle-recoil-buffer-system-final/
Great videos BTW. The info and effort is excellent, and appreciated.
I read in your docs that you used the Kynshot R5000HP hydraulic buffer with a 3.25" length. Why did you use that with the JRC long buffer tube and not the Kynshot RB5015HD with a 3.9 length? Kynshot says that one is designed for PCC's. I've never used any kind of hydraulic buffer, Kynshot, or anything else. I might try this so I'm curious as to why you went the way you did.
On my site there are additional configurations for "gentle" recoil, and each group of parts - tube, weights, and buffer - is very specific and can't be mixed/matched. Together they give the right travel and spacing for the 9mm bolt in the receiver, otherwise damage could occur. The 4" is considered "PCC" because it's too heavy for 5.56 and the length is correct for the generic typical configuration of a 9mm bolt with a carbine tube. The 5000HP measured as about the same piston compressive force as the 5015HD, it's just a little shorter and lighter. Adding a spacer weight in front gives it 4" total (PCC length) and is slightly heavier than the 5015HD, giving a slight mass advantage. Hope that helps!
I might give that a try thanks.
Yes! I've always takes umbrage with the springy twang of the M16. I liken it to an old screen door with a simple spring closing mechanism. Anyone that I ever described it to - even having just fired a round - they tend to not know what I am talking about. I find it very distracting. And it makes me feel like the rifle is lower quality than it should feel. Like a toy that could kill you. And that's a bad feeling to have.
Did you do any testing with the kynshot RB5020SS HYDRAULIC 9mm Buffer?
Man your videos and research are second to none! I truly appreciate your videos and shared knowledge!!! That said, I have a question, Will the kynshot competition short stroke 7.7 oz buffer work the same in an 8” A5 buffer tube without the added spacer weights? I’m building an aero epc9 with the b. King 9mm bolt.
I haven't played with their competition buffer yet, but as long as the bolt travel distance is right, it should work. I check for proper travel distance by making sure the bolt face stops about 1/8" to 1/4" behind the bolt catch when the CH is pulled all the way back (and the piston is compressed).
Just an update, the competition short stroke ran flawlessly in the 8” A5 tube. Bout 200 rounds through it and no malfunctions or failures to feed with 27rnd pmags. Feels smooth as butter!
Extended buffer tube used only with this particular setup and not the other ar9 buyers correct?
The tube length is critical for getting the correct bolt travel with all the additional spacers. Check here for the tube/parts combos that work: blowback9.wordpress.com/2023/05/28/9mm-ar-gentle-recoil-buffer-system-final/
Love it! Building my ar9 currently
Very informative video! I was going to order the spring but I saw the update about it not fitting the Kynshot buffers?
It's hit-or-miss. I'd go with a Tubb AR-15 spring instead.
What are the pros/cons of the heavy 10 lb. hydraulic buffer vs. the standard 5 lb. hydraulic buffer?
I like the "feel" of the 10lb a little better, some folks like the 5lb better. Either one should work fine. Get whichever is cheaper!
@@Blowback9Thanks, Doug. And you're right about Botach. The $130 buffer changes to $90 when you sign in!
Will just the hydrolic buffer by itself make follow up shots flatter?
I recently bought the Palmetto State Armory PX9 Gen-4 rifle. WOW the amount of crud that is blown into the receiver and out the ejection port!
My brother is left handed and can even see the amount of powder residue being blasted on his face! The brass casings are even ridiculously covered with crud and quickly turned the costly walnut media in my tumbler into looking like I am tumbling with charcoal.
I' m now seeing these exact same complaint from even years ago, and so it's pathetic that any company would still be letting their guns leave the factory with their schitty light weight buffer. Theyre charging an average of 800.00 for the gun and yet theyre then making us pay for the PROPER 8oz buffer which significantly helps keep the bolt closed longer in order to keep most of the crud in the chamber and it reduces the recoil
All the details: blowback9.wordpress.com/2023/05/28/9mm-ar-gentle-recoil-buffer-system-final/
Just another observation; there seems to be a lot of debate as to whether to go with more weight and a standard M4 spring or more spring tension (308 or similar) and less weight, or a balance of both.
Yes, there's a lot of debate, now that the myth that a .308 spring is somehow beneficial for 9mm has been challenged and shown to be without merit. No one has ever provided any empirical evidence that .308 springs are either necessary or beneficial. Instead, the've been connected to many significant problems with the platform that are resolved by switching back to regular strength springs. More info and analysis: blowback9.wordpress.com/2021/04/07/the-case-against-308-rifle-recoil-springs-in-a-9mm-ar/
@@Blowback9 Read it. Very compelling.
Great video! Now that Wilson combat has changed their spring, what spring would you consider?
Tubb AR-15, Tubb Lightweight, AR Stoner, Spinta
Theoretically, could one use the KynShot shorty .308 hydraulic buffer RB5004 (2.5" long and 3.8oz), with 2 of the 2.5oz, .75" long spacers, in a standard length carbine tube, totalling 8.8oz in the tube? Weight would be down by 2.2oz under your setup in this video @ 11oz but you keep the shorter tube. I suppose one would have to experiment in their combo. I run an 8oz buffer in my 16" home build, and feel it is not under weighted, atleast not severely anyway, and that is just a standard buffer without the hydraulic dampening effect.
I digress, I am running the 11oz AR Stoner extended (blue) buffer in my home build. It is 4" long exactly. Damn, the extended buffer tube looks to be the way to go.
I tried that exact setup. The 5004 has a shorter piston and just didn't do as good of a job, but it's an option!
I’m curious what the shortest pull length is with the 8.5” buffer tube and how many adjustment holes in the Just Right 8.5” buffer tube.
Have you tried the JP silent capture 9mm setup? Wondering what you thought. I just don’t like the thought of a hydraulic buffer, seems like a high potential for failure
Keep in mind your length of pull folks.(ie ar-pistols) The three letter bois are always looking for a new canine to shoot. If you dont know about lenght of pull you need to research.
I can't find "length of pull" anywhere in the NFA or GCA as passed by congress. SCOTUS recently killed Chevron deference. Food for thought. I am not a lawyer, this is not legal advice.
Hi, I went to Botach website and the description for the 9mm buffer (RB5015HD) says it’s for use in 8” barrels or greater. I’m running a 7” barrel. Have you tested this system with barrels shorter than 8”? Thanks.
Yes! It works fine in my shorter barrels.
Have you tried or heard from anyone who has tried using this system with a PSA AR-V? I didn't see any mention of it on your website, but I imagine it wouldn'thave any issue. I find the Scorpion/U9 mags to be the most aesthetically pleasing as well as being cheap, available, high capacity, and reliable to my knowledge, so it was high on my list for AR9 candidates.
Should work fine!
Thanks for all the good information 👍🏼
You bet!
5 star video
Sir, what is your opinion about the Armaspec 9mm buffer spring?
Excellent info, thank you!
Fantastic video, I wish I had seen this sooner! Is the Spikes 9mm bolt good for an EPC9 upper build, or should one use one of the bolts on your website?
That bolt should be fine.
Thank you for sharing all your research. Being from NJ I will have a 16" barrel on my 9mm AR. Im definitely going to buy this buffer system but do you have a recommendation on BCG?
Any recomendations for what buffer to use with an a2 rifle length buffer tube?
Ever used the kaw valley pcc spring? I have one with a vltor stainless buffer, haven't used since I still need a handguard for it, just curious if you've tried a similar combo yet
No. XP springs are not necessary or beneficial for 9mm. They can cause a bunch of problems, instead. More here if interested: blowback9.wordpress.com/2021/04/07/the-case-against-308-rifle-recoil-springs-in-a-9mm-ar/
@@Blowback9 I did not realize that it's just a 308 spring, sob. Well the lower that I plan on using has a strike flat wire so I'll just swap the buffers when I need to and keep the other spring for whenever I get around to an ar10 build
I’ve got a JP GMR15 with a Aero Precision buffer tube. It is 7.25” in length. I’m looking on your site at the recommendations and I’m not sure which to go with the Kynshot RB5000 or the RB5015HD. Ordering the Tubbs flat wire for it but I need help on which buffer to choose thanks.
I only ask because you have a 7” buffer tube listed or 7.75” option. Mine falls in between
I have an Aero Precision carbine buffer tube sitting beside me - it's 7" internal, the same as a standard carbine tube. Don't count the long "tongue" sticking out the bottom open end. Measure at the top.
Right on!! Thanks for the help!
Ordered the Kyn-Shot Rb5000hp and Kynshot spacer with the Tubbs flat wire from the link on your site. Can’t wait to test it out!!
I’m thinking about putting a Devil Dog Side charger on it too, have you used one of those?
I have not used the DD. Let me know how it goes! @@nylesreynolds2324
Would you recommend this setup for a 5.5” barrel with a 4 inch suppressor and a law tactical folder?
I know you mentioned getting as much weight as possible with suppressors and wanted to confirm with you. Thank you!
Sounds a lot like one of my setups. It should work fine. If you use the "original" gentle recoil setup, it'll be 11oz in the buffer tube.
First off thanks for sharing all of your information and thoughts about AR-9 mechanics/physics. Question for the blow back recoil system improvement on this platform: would inserting a 24mm - 25mm diameter 5mm - 10mm thick rubber washer/gasket pad with a hole in the center the same size as the end of the buffer tube at the rear help reducing felt recoil? what are your thoughts seems to me that could help reduce/absorb some felt recoil but I'm not sure how negligible the improvement might be.
Sounds like the Tacticool buffer for the Sub-2000 - check it out. It should have an effect on the felt impact of the buffer. The hydraulic buffer piston essentially serves the same purpose in the gentle recoil system.
Awesome video! I’m running a law tactical folder with their 2oz extension. Would you still recommend this setup in the video? Thank you
I haven't tested the full size GRS with my law folder, so I can't guarantee it, but I can't think of any reason why it wouldn't work.
testing it out tomorrow, thanks for posting all this. I looked but didn’t find any discussion on barrel length running this system, does barre length not really matter? I have a 8” for tomorrows range day but thinking about swapping to a 5”.
testing it out tomorrow, thanks for posting all this. I looked but didn’t find any discussion on barrel length running this system, does barre length not really matter? I have a 8” for tomorrows range day but thinking about swapping to a 5”.
@@dereks3016 With the GRS, it functions with any length barrel. Shorter barrels will have less felt recoil. That's the only difference.
man i wish i had seen this 6 months ago. Im now wayyy to deep "additively" building a mp5 with an ar lower.
however, matador makes an all-in-one upper that had my eye as well. v I wonder if they did anything to resolve the recoil or not.
I have one of their uppers and will be reviewing it soon.
I look forward to it!
How would you retain the recoil characteristics of this system while incorporating a LAW tactical folding system? My initial thoughts are to weigh the LAW plug and just cut enough of the weight from the bolt needed for the plug to insert and then reinstall it, comparing the amount cut from the weight to the weight of the plug to see what the difference is. Has anyone does this while using this "Gentle recoil system"?
With most bolts, the cylindrical internal weight is 2.5oz. My Law plug is about 2.2oz., so the weight difference is minimal. The GRS works fine with my Law system build.
I was wondering if you could help me with feeding issues....i just finished my build and used your grs with all the parts listed on your website. I have an 80% glock lower with a gibbz arms side charging upper, and a faxon bcg and faxon 8.3in barrel.Just tried it out for the first time and with only putting 2-3 rounds in the magazine at a time, the bolt would not seat all the way. Any recommendations?
I have exactly the same Hydraulic Buffer and long flat wire spring plus one of the 3/4” 2.5oz spacer weight in my S & W Response with the factory 7.25 or 7.3” buffer tube. Big improvement in felt recoil. I tried adding a second 3/4” 2.5 oz spacer weight but that didn’t allow enough room for the bolt to lock open. I’m wondering if I will be able to tell the difference if I install the 8.5” buffer tube with the 2nd 2.5oz spacer weight… Ummm
In my experience, adding the 2nd weight makes a noticable difference.
@@Blowback9 8.5” buffer tube and 2.5oz weight are on their way.
Is there a buffer tube "recoil buffer" similar to the ones that Mcarbo, Missouri tactical, and tacticool products offers for the Sub 2000? I think extar uses a somewhat similar "system" in thier buffer tube as well. Do you think this would reduce ar9 perceived recoil?
You mean a neoprene-type squishy thing? Not that I know of, but that was my inspiration for using a hydraulic buffer. I had a tacticool buffer long ago in a keltec sub-9 (pre-sub2000).
@@Blowback9 yes. Thats interesting. I might try to modify a sub2k recoil buffer or try to make something similar. I think it helps in the sub2k
How does the MPX stack up to the Gentle Recoil System and MP5?
MPX is better but not as reliable and more expensive.
So - now that this matter has been settled - what about 45ACP? ;)
By chance would all the info on your channel apply to the Freedom Ordnance FX-9? I know the specs on the lower/upper are a bit different than an AR9
Can you tell me about what kind of buffer tube, spring and buffer I need for ar9 pistol, thank you
Here you go! blowback9.wordpress.com/2021/08/09/what-9mm-buffer-do-i-need/
How does this system work for competition with shooting fast, double taps, etc.
Not great. Most serious competition shooters say it is a bit too "spongy" for timed competition games.
@blowback9 Have you tested the CMMG delayed recoil system combined with your gentle recoil system? Really interested to hear what you think of the combination
CMMG uses their system in the Resolute 9mm model and full buffer tube.
The two aren't compatible with each other because of the weight, but it's reported that a plain hydraulic buffer will work with the CMMG RDB system.
How does this compare to the scheel roller delayed buffer? Or to the combo that max Leograndis used to use? (Rb5020ss, springco orange, a5 tube, short stroking spacers)
Softer and slower than the scheel. The scheel can tuned for better dot movement but this is much better across more ammo types.
The max combo is great for soft reloads but has more felt recoil and is snappier/ faster for sure.
@@ZChaosFactor thanks. I just ordered the maxim rdb. Eager to try it out.
Do answer these comments? Got receiver milled good ,got your suggested 11oz weight and flat spring. Do I really need 8.5 buffer tube???
I try to. You don't need an 8.5" tube unless you're trying to make the Gentle Recoil System. A regular carbine tube, 11oz. buffer and flat carbine spring will work just fine.
How would you compare this to Congo RDB Ssystem
Not aware of that one. I'll have to look it up.
Would this set-up accommodate a 16 inch OAL barrel?
It should. I use it with my 16".
Hey so which setup would you recommend for a competition PCC with 10-12 inch barrel length? I want to go with as fast double taps as possible, preferably with lowest possible recoil.
I don't do competitions, but my understanding is that the lighter setups are better for reducing dot jiggle even though they produce greater felt recoil. I'd try the lightest buffer setup that's appropriate for the bolt's mass (bolt+buffer total around 22oz.)
This may have already been addressed, but is there an additional benefit from combining this system with the CMMG bolt/barrel?
No. It's too heavy for the radial delay. Some folks do use hydrauilc buffers with the CMMG, I'm just not sure of the setup. Try c3junkie.com.
Would the Veltor A5 buffer tube with A5H4 6.8 oz buffer work if keen shot got to cold in the winter?
Yes, but it wouldn't cushion the buffer's impact in the back of the tube. A KAK K-Spec may be a better option with the spring dampened head.
I'm going to build this, assuming all the parts are still available! Thank you!
If you sign up at Botach and log in, the price for the hydraulic buffer goes down a lot.
@@Blowback9 I'll say! Really appreciate you sharing your experience and knowledge. I'm staying tuned for sure.
@@Blowback9 I've got all my parts! 3 weights plus all the rest definitely added a nice bit of heft, I'm here to thank you again for being such a resource.
Reason being, I haven't had the chance to take it to the range, but manually operating the action has my ejector barely flopping them out but usually failing.
Saw the page on this issue and I'm going to be able to easily fix it because of you
@@Blowback9 So I'm unfortunately using an Aero EPC9 lower and the extractor can't really be bent, do you happen to know anything more about this lower?
I probably should have taken it out to the range before trying to troubleshoot ejection, it just doesn't eject if I manually operate things.
Have you tried the B&T AR-15 hydraulic buffer?
Not yet - I'll have to look into it!
I’m back with my results now that I’ve built a GRS in my 7” FM9 and tested it out. I went with:
1) VLTOR tube
2) Kynshot RB5000HP 4.8oz
3) 2 weights totaling 5oz
4) WC flat wire spring
Does it work? Absolutely. Is it worth $196? Not even close. But that’s okay. I enjoyed the process and it’s still 1 of my most favorite ARs to shoot. I still plan on making additional modifications. The stock FM bolt is 14oz. I’m going to upgrade to a 16oz eventually. I see Faxon has a 16oz bolt. Any recommendations on it or something different? Thanks again for all your testing. It’s a wealth of information.
Although it wasn’t worth the money to you, how was the overall performance of it your FM9 compared to stock? I recently got one and thinking about doing a similar recoil system in it.
It performs amazing. 2 weeks ago I got to shoot mine next to an identical stock version. It’s at least 15% softer. Half of that is due to the increased weight. I’m happy with the end results. If $ is no concern, I say go for it. If on a budget, I would focus on other things 1st.
@@scott2228 Great, thanks for the reply. I think I’m going to start with the kynshot buffer and a springco red carbine spring. I see another build that had that and it ran so smooth suppressed with just that.
On a separate note, I’m curious to if your FM9 had any problems with feeding using full 33rd Glock mags. My mags work fine as I’ve only had them at 60% while im breaking it in but I put a few extra in one of them and it jammed second shot. If they are full the first round jams after dropping the bolt, seems like there’s too much pressure in the mag. And a few occasions my trigger didn’t reset when I first took it to the range but seemed fine as I shot my last few mags towards the 200 round mark. Did you ever experience this same issue?
Sounds like a good starting point.
I never load past 30 rounds. Those last 3 rounds just seem silly to me. Every once in a while I’ll get a hang up on a full mag with the Kynshot. It’s never happened with regular buffer.
Speaking of regular…. I got great results using FM’s 45ACP bolt and the SprinCo Red.
@@scott2228yeah I wouldn’t load them to 33 either. I load mine to 30 and it seems to be an issue loading the first round.. granted I hadn’t got past the break in point so idk. Figured the mags maybe need to loosen up a little bit. Are you saying you had occasional issues with the trigger resetting when using the kynshot?
If it hasnt been said or questioned down in the comments and or if you have explored this type of setup. Your setup; weights, buffer and all, with a Geissele super 42 spring and a law tactical folder, your input/2 cents/ opinion? When i installed the law tact folder on my ar15, I needed a stronger spring, hence the geissele, to reliably feed. Looking forward to building a more serious PCC. Thanks, good stuff you got!
Thanks! I did an article on the Super 42. I wasn't impressed, but to each their own! Here: blowback9.wordpress.com/2023/05/02/geissele-super-42/
Follow this guys advice!!!!
Oops. I had the weights in the tube first, then spring and finally buffer. It still worked but I moved the weights behind the buffer now. Does it made a difference?
It should be spring first, then buffer, then weights in the tube. The weights are between the buffer and the bolt. You should notice a big difference.
@@Blowback9 sounds good. It worked but I had it wrong. I changed it and I’ll test it soon. So far everything works well because of your guide . Thanks
Is the 5015hd the same length as the 5007? I went to order the 5000hd but out of stock so got the 5007 pairing with the 8.5 tube and 2 spacer weights. Will this configuration work for a 16" barrell?
The 5015 and 5007 are the same length. The 5000HD is 3/4" shorter. That configuration should work with a 16" barrel.
So I have all this setup, your one of the few who mentions those spacer weights, is this necessary what exactly do they do?
They add mass to the buffer system. Extra mass helps slow the bolt/buffer and reduces perceived recoil.
How would this compare to the Maxim Defense roller delay buffer? Also, what length spacer would you need in the rear for an A1/A2 buffer tube? My current setup is a 16" Foxtrot Mike FM9 with a Doublestar ACE ARFX 10" fixed stock, and i used a spacer from MidwayUSA to make it carbine length internally for the Maxim RDB. I also had to remove 0.084" (iirc) from the spacer for the RDB to fit properly. I currently have 570rds through it with 0 malfunctions (all S&B 115gr fmj) and recoil isnt bad at all. The thing that i don't like about the RDB however is how hard it is to overcome the ball bearings when pulling the charging handle back. After 570 rounds it has gotten noticeably easier, but is still pretty difficult, and I'm a pretty stout guy. Everyone ive showed it to thought it was seized until i said jerk hard and they got it. Im thinking of building another but regular blowback (i went with the RDB for weight savings). Oh also i removed the added weight from the bolt for clearance with the RDB. Any ideas? Thanks!
If the new post May 2024 Wilson Combat Flat wire spring no longer fits the Kynshot, what buffer spring do you recommend as an alternative that will work?
Tubb AR-15, MidwayUSA, Spinta all fit really well. More here: blowback9.wordpress.com/2023/03/03/flat-wire-spring-comparison/
What combination do you recommend for an AR-40 with a carbine length tube?
I don't have .40's, so I'm not sure of the best setup, but I'd go as heavy as I could.
Last question, how long is the Flat Wire Buffer spring when it is out the tube and laying on the bench?
Depends on the spring. I have 15 different kinds. Around 11"-15". Measurements: blowback9.wordpress.com/2023/03/03/flat-wire-spring-comparison/
Since wilson combat changed their spring dimensions do you recommend another maker for a flat wire buffer spring that fits over the kynshot?
Tubb carbine, Tubb lightweight, or AR Stoner fit. I'm working on others.
Will this setup work on a typical AR15? Im trying to make a flat shooting laser pointer. Do I need to purchase the 8.5 inch long buffer tube plus the correct hydraulic buffer plus the kynshot spacer weights if I wanted to run the same recoil dampening benefits on an ar15?
This will not work with a normal AR-15 because it's gas-operated, not simple blowback. It has to be balanced in different ways.
If I have a std length, mil spec buffer tube could I get away with 1 spacer weight? OR would you recommend just running a gold top with flat spring?
I would use an RB5000HP buffer and 1 spacer weight with a carbine tube to get some improvement over a standard buffer setup. For a larger improvement, I'd swap to an A5 tube and use 2 spacer weights (with the same buffer).
Reno May said hi
What did you find to be the optimal ammo grain weight to use?
I never specifically compared grain weight, but 147 seems to produce less rearward force. In my Overmass Project, 115 would cycle when 147 might not, so it appears the 147 was producing less blowback energy.