Lapping Rifle Action Lugs will DESTROY your Rifle! Don't do it???
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- Опубліковано 5 вер 2024
- In this video, I'm going to debunk this attitude and general misinformation on this particular subject. I've read a lot of comments, videos and forum posts that lapping bolt lugs should ONLY be left to professional gunsmiths as you can EASILY screw up the headspace specifications of your rifle. Is this true? Watch & make your own conclusion.
Rockwell C scale does not go to 200. in order for AISI 4140 to have a hardness value of 200+, you are using a Brinell scale. You ratio is roughly correct though.
Correct. Diamond is 98 n the C scale.
KnifeMaker
Savage doesn’t need to be lapped . That’s why they have a floating bolt head . Very good set up. They Aline them selves
The things like lapping the bolt,aligning the bolt, and lapping the bore have been done since before I started shooting in the 70s. Lapping the bore is especially beneficial to accuracy and ease of cleaning. We used to use different grits of valve polishing compounds and JB bore paste.
*To "adjust" headspace on your Savage rifle with separate cinch nut barrel retention system... GO GAUGE required. Break barrel nut loose so that barrel can move. Insert go gauge and a .002" brass shim between go gauge and bolt face.. Finger snug barrel against gauge... tighten nut. Test your adjustment with go and no go gauges... and, repeat until satisfied.*
A lot of this goes back long before what we buy today, when many gun parts were made of softer metals for the machining processes - the Winchester 52 actions come to mind here. The receiver was surface hardened, or case hardened, after it was machined - that is a part you do not want to lap. We are not playing with those kinds of steal today.
Case hardened steel goes at least .020" deep so a lapping job of .002" will be fine..
Hey brother, fellow Texan! I am outside of Round Rock. Throw me an IPA, because I'm that close! Lapping your action, even with aluminum oxide 240 grit will barely take the sharpie marks off your bolt, so I'm definitely in your camp. Dude I'm really enjoying your videos thank you for the time and effort it takes to edit and upload! 👍
Head space is overrated, Because if you're reloading, your going to measure your shoulder for shoulder bump.
Nice test. Much appreciated. It may be that what we learned is that lapping a factory action may not remove enough material to make any difference.
Most actions will come true with .0002-0004" of stock removed from the lugs. Reloaders will size to proper headspace for their chambers anyway. But yeah lapping is a big thing ... for one-piece bolts, anyway. Cheers.
I just fully polished out my parts and
have the same thing right happen.
I'v been doing polish on parts for years
from the 90's and with great results.
That's the difference between expensive and cheeper 🔫 what I've seen in gun shops.
Savage 110E, lapped the lugs, oil smudged every 60 turns.
World of difference in groups. 10 inch down to 3.
Humor, I hope
I agree 100% with your stance on the subject.... but this test is pretty flawed. The aluminum is 1/5 the hardness but the surface area you are lapping with the aluminum stock is significantly larger dispersing the surface pressure over the abrasive material.
Consider you are sanding your furniture with block vs 3 fingers. The block will remove less material than the points of your fingertips given the same applied pressure.
That's what I was thinking.
In addition, aluminum being soft tends to clog up abrasives, unless they are made for use on aluminum.
6063 aluminum with a Rockwell of 40 on the C scale? Sorry, but that is simply not possible...nor is it possible to get 4140 to a Rockwell of 200 on the C scale. Completely accurate about hand-lapping being a very slow/small material removal process, as well as the steel being at least 4 times harder than the aluminum...just completely wrong regarding the Rockwell C scale hardness numbers you were giving. You were giving Brinell hardness numbers, not Rockwell C scale.
I am a retired toolmaker… you are correct. Too many “experts” disseminate false information… this video is another example
Point made, for sure. Compounds we use are far from too aggressive or damaging. btw, I wish the chamber lengths of guns I have in the same caliber varied within only 10x of the tiny amounts I've ever lapped off lugs. I use the Hornady COL tool with case bushings, and fired cases from the same gun don't always measure within a whole thou when I set up my dies to reload 'em. Most guns will clean up within less than half a thou. That said, while I'm happy to lap any/every action's lugs an improvement can't be assured, but possible harm is laughably unlikely, what this video is about.
Pretty sure the softer material will hold the lapping compound and cut the harder.
Wheelers use aluminum oxide abrasive in their compounds because it wears out quickly. If you ever sand blasted with aluminum oxide you know that once it wears out it does not work for nothing.
If you used a diamond compound more material would have been removed. Abrasives are complicated, ask your local mold maker.
Quote "When taking a rifle to its full accuracy, lug lapping should be a last resort." Any tiny uneven tension in the action has a high probability to cause problems with accuracy, like occasional flyers... To optimize the rifle action you need precision tools and expert craftsmanship to be successful. I my opinion, If what you do can't cause problems, then it's highly unlikely that it has any possibility to do anything that might be beneficial. If you just want the part to look nice, you might be able to do that without doing any harm. But if if you want the rifle to be more accurate, that is another ballgame all together, that requires work that changes tolerances/properties. Here is a gunsmith explaining: ua-cam.com/video/0lzGzKBh_AE/v-deo.html
Hmmm. I wonder how i was ever able to lap burnt or rusty valves in auto mobile heads so they were perfectly sealed. After all, valves are harder than aluminum. No big deal on the Savage or a Remage barrel because headspace is adjustable. As to the guy who said 240 grit would barely remove sharpie marker marks, i laugh in your general direction.
only matters for factory ammo or saami spec. any reloader will just adjust head space and call it a day :)
Or if you want to use the same reloaded ammo in two different guns.
Lapping bolt lugs is a very specific solution.......not a general do-all fix. If your receiver lug seats are cut perpendicular to centerline and the corresponding surface on the bolt's lugs are also perpendicular to centerline and the machining process left a good surface finish.......no need to lap.......lapping will only AT BEST keep these surfaces true but MORE LIKELY you will lap these surfaces untrue because of uneven pressure, uneven lapping compound, etc. If you decide to lap a factory rifle, realize any leftover lapping compound will continue to lap or imbed itself under extreme pressure.
Whatever 🙄
So at least 1 question, would be “ is it necessary to lap the lugs on a factory Blueprinted action ?”
To get good results when lapping scope rings, it's important to KNOW the diameter of the scope you intend to use, and match the lapping rod to that same diameter. Just cause it says it's a 30mm scope doesn't mean that it is EXACTLY. MEASURE IT TO BE SURE!!!!
just use Burris sig rings..problem solved
If you want to prove if it changes headspace, why don't you set headspace on your Savage and then lap your lugs and then recheck headspace.
Your experiment is not an accurate representation of what you are trying to prove.
All high end bolts and receiver's are lapped . That's why low end ruger American tier rifles sound like a zipper when the action is ran. Because they were not lapped after machining
So you want to take close factory tolerances and loosen them up ? & that's a good thing ?
The other side of the coin to this is: if it hardly removes any material, is/can it really correct unequal bolt lug contact? Is the error really THAT close?
Yes
Get the gages to checkbwhen your doing it
Rockwell scale numbers above 100 or below 20 are unreliable. And most receivers, the hardest one I've ever seen was a Ruger Model 77 receiver from the early seventies and it was up in the 70 or 80 range. The bolt material is usually just a little bit softer than that. But it would take a hell of a lot of lapping to grind away 1000th of an inch from it. All you're trying to do is make sure that your bolt engagement is consistent. And the receiver isn't even in the mix because the bolt locks up into the barrel. But the reason that making the bolt engagement consistent is because if the round goes off and pumps 60,000 lb per square inch of pressure inside that chamber and one of three bolts is engaged before the other two or one before the next one you cause a torque moment within the barrel that starts a barrel vibration that degrades accuracy.
And just to be fair you just did 200 laps, because you were doing two for every time you were counting one. Forward and back is two strokes not one. And that's about correct what you're showing on that aluminum.
I only question would be is why in the world were you even buying 320 grit lamping compound. 400 would be a minimum and 600 would be what I would begin with. You want to sneak up on it, you don't want to grind it away.
Good video and agree with your assessment .
Can you screw up your rifle?… yes. But it would take some effort or genuine carelessness on your part.
You CAN get good information online. But remember… gunsmiths aren’t likely to give you advice that would lessen the likelihood of your needing to bring your gun to them for repair either.
Think about what you’re doing & be sensible and careful. Stay between the lines with your coloring. 😉
brownel's has videos on Remington 700 rifle & action ps they come apart with right tools! ( a few big apes & big hammer to will help) they fix the action and lugs in action with tools & straiten the new 700 dollar rifle out! after it all done like 2000 or more dollars to do the stuff they did with the tools like 300-400 in tools for action removal & torque back & barrel vice & go and no go gauges ps savage barrels have nuts to lock barrel in place
Remember it’s times two your removing material from the lugs and the action.
Confusing, you keep saying half of ten thou aka half of .010.. do you mean to say a tenth of a thou, as in .0001? The Brinell scale is a macrohardness test and is not necessarily a good way to asses wear resistance off hardness alone
Thank you. I’m a machinist and that was driving me nuts. Tenth, it’s a tenth. That and calling the micrometer a caliper.
@@bradleycampbell1634 LMAO, ME ALSO I don't know what in the hell he was trying to say.
Naysayers are compensating.
Any updates on the rifle?
More for a solid bolt
*Yes. Lapping the lugs can and will increase headspace. This should be done before the barrel is fitted... Or, if the barrel is already fitted... and you feel a need to lap lugs... plan on re-fitting the barrel.*
Just says Carbon Steel !!
You're confused as receiver lugs faces & bolt lugs faces are lapped with the barrel removed. No wonder why you think a futile effort. No one I know laps lugs by using their hands and rubbing back and forth on the bolt.
Hell car mechanics use a bolt on machine to lap valve seats. Why to apply pressure and increase frictional forces! This isn't sanding wood, its lapping metal. metal and fricitonal; coefficient forces must be applied.
Heres a formula so you to can figure out a friction coefficient. μ = F/N, N being normal force and f being frictional force. Think of lapping like brakes on a car, a piston in the wheel cylinder moved by a hydraulic force causes grit on the brake pad to rub against steel. Every time it does this metal is removed. It's the hopes that the brake material wears out first. as its easy to replace. None the less when you apply brakes you are lapping your disc rotor or drum.
Lapping of engine valve ports also requires pressure and the machine is bolted on the head usually and a mechanical force is applied along with a lapping medium.
Okany pressure is needed to properly lap. Thats great as when you close a bolt on a gun there is a mechanical application of pressure. If you apply a lapping medium to that bolt "rear " face the mechanical advantage reveals about 20-100 foot pounds.
Now if you would of said its okay to lap lugs while the barrel is removed you would of hit the spot. And it's a perfectly good method of ensuring the reciver lug face sits at least 80% flat against the bolt lug "rear" face. Second allot of material can be removed with barrel removed as I stated because of pressure on each grain of grit. A static force of 80 to 100 ft lbs is common but that could be wacky if the lugs have high and low spots. Which most production rifles have. Thus the reason for added protection by recessing the barrel a tad.
ONCE THE BARREL IS REMOVED. All you need to accomplish lapping lugs is a vice, a few ranges of lap medium and Rifle lap lugging tool for your brand of rifle receiver. The tool screws into the barrel female threads. The you set head space when attaching the barrel and using a go gauge for your caliber. (attaching a barrel is easy, but don't do it until you understand the dynamics of head space)
I am still laughing as your title shows a lot of ignorance. "Lapping Rifle Action Lugs will DESTROY your Rifle!" TELL ME HOW DO YOU EVEN SEE WHERE TO APPLY LAPPING MEDIUM WHEN YOU CANT SEE THE RECEIVER LUGS WITH A BARRELED ACTION! let alone get your finger in there to rub them a 100 times!
You right bout one thing! People write things on the internet they know nothing about!
.
You really should learn what you're talking about before trying to teach others.
YES PLEASE, Stick to furniture until you know what tool you are using & learn how to read that tool. I'll give ya a C- for effort though.
Dude look Up aluminium oxide.
Lapping is an art and not everyone should try it. I know plenty of folks who use toothpaste to smooth up actions, but I would rather tear it down and do any stoning or smoothing in a conteolled manner o ly where needed and save any wear on other parts.
The carbene fiber barrel don't let the barrel cool down ⬇️ I stop 🛑 using
theme because of that.
The action and bolt lugs are always lapped BEFORE head space is even set to begin with when building a rifle, except on cheap mass produced factory rifles. Which is one of the many reasons people build a custom or have one built for them. Even high end custom shops do this as routine as drinking water when you're thirsty because even the best turning tools leave machine marks. Use layout dye, find out where the high contact points are after cycling the bolt in the action a few times...again there always will be some as cutting tools leave marks, especially after they have been used on some previous builds. Lap only enough until there are no high spots and the surfaces are mated to as close to 100% contact as possible. Now on Antique shit that's only surface hardened it might possibly become a problem if you waaay overlapped like a dumbass inbred drunk hillbilly without a clue in his home garage and went way past the surface hardening. I'm guessing that the obsession with "hardness" comes from the opinions of writers, not builders... from many many decades ago, who's only guage of metallurgy was scratching with a file like the old blacksmiths did to test hardness on knives, tools, etc. and who may or may not have had any other understanding of metallurgy, headspacing a rifle, how a rifle goes together and the order in which operations are done. But I bet they could drink, yak, and accept the hell out of sponsorship's. There are a lot of other rants to be had at those old "knowledgeable" authors, ie. the ignorant opinions about drilling holes for gas vents not significantly weakening the structure of a receiver ring - when in practice the least that a circular hole will do is to double the stresses, and in many cases such as old Argentine Mauser's it will raise the stresses far more than two fold. The worries are from way back in the era of the old 1903 Springfields and Krag rifles, long before we had better alloys and a better understanding of metallurgy. Even on those rifles you'd have to be pretty damn aggressive, and not paying attention at all rather than just to remove machine marks and square up surfaces to each other to ever begin to lap beyond the depth of the case hardening. The one's saying it effects head space probably have never head spaced a rifle. Most above 40 IQ people know you true the action, the bolt face, lugs and surfaces first, then after those operations have been completed, and only then.. finally attach the barrel and then set the correct head space. That older metallurgy is exactly why 30-40 krag and 30-06 ammo is held to lower pressure than say a 270 Win. Factory Ammo makers have to ensure their ammo will be safe in the oldest action that the caliber was chambered in, as some idiot not knowing those old actions can't take modern loads might actually pick one up and shoot it if they loaded those rounds to modern era action pressures. That why some reloading manuals have several sections for the 45-70, one for old Trapdoor Springfield's, and another section for more modern guns. Another example is some manuals have different loads for the 6.5x55 Swede, one for the older original rifles and another set of loads for the modern.
Did this on my Remington 700, 7mm mag 30 years ago along with pillar bedding and adding a custom trigger. All this turned it into a moa rifle at 100 yards.
it depends on whether or not the action is custom or factory. If you blueprint/lap a custom action you will completely mess up the headspace and it isn't needed for a custom action. Lapping/blueprinting with just the action is a really bad idea and it will jack up headspace. You always wanna do that with the barrel and action.
If you make a informational video at least know what you’re talking about… might want to take a class in metallurgy and heat treating processes 🙄🙄
Gig’Em 👍
Dude you could have spent a few mins to learn the correct terms for referring to the bolt and action as what your talking about is quite technical and due to the use of incorrect terminology, it’s very confusing and misleading. You said you would take hours of research related to producing a video, but you didn’t do it enough on this one……. Bummer as it would have been very nice to have this make sense…..