To peen or not to peen my m14?

C

C.308

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Greetings!

I've been thinking about shimming my gas system, and found some shims available. I was about to order them. But then I got to thinking...

Peening.

Its been mentioned in a couple threads. As well as on some other online resources. ( I don't mean peening the splines to tighten the gas# cylinder.)

I mean peening the barrel buttress that the shim would sit against.

How exactly do I peen it? Just tap it around the edge of the buttress until i get the results I'm looking for? Or on the flat face of the buttress which the shim would sit against?

Any info I find on peening the gas system is regarding inside the splines and not the barrel buttress.# Its discussed and advised as an alternative to shimming for good gas lock timing but not with any direction for newbs like me.

*I do plan on buying the Jerry Kuhnhausen book asap.

Also I'm not looking to turn this rifle into a precision shooter. Tight, safe and reliable is good enough for me. No issues with gas port alignment. Just a floppy band and an out of time gas lock (around 11:00-11:30). I also dont want to over do it and push the port out of aligment.

Many thanks in advance!!
 
Have you tried flipping over the gas lock?
It will lock up in a different position. You can also try other gas locks if available. I have several if you pay the shipping I will send you them and you return the ones you don't use and your old one.
 
Thanks for the advice! It seems to be the thing to do except mine is a DA socom and has a gas lock front sight which doesn't allow it to be flipped. But... pm on the way.
 
I showed guys how to peen the gas cylinder buttress at my clinics. Not aware of any of our other gurus recommending anything other than shims.

for peening the buttress in the home shop , you need a small ball peen hammer and a steel surface to work against. With the barrel tipped against the steel surface and with very accurate smart blows, you form the metal forward as you evenly rotate the barrel. After every revolution of the barrel, check for fitment. Perfect fitment consists of a perfectly aligned gas port and a gas lock tightening at the 4:30 position by hand. Tool tight as 6:00

The professional way to perform this procedure is with a lathe equiped with a roll peen assembly and it's pretty straight forward if you are familiar with such tools.

once the procedure is complete and you are satisfied with gas lock position and port alignment, then you peen the edges of the splineways to negate any rotational play. This is done in such away to align the gas port even more precisely.
These two procedures , when done correctly, provide increased likely hood of stable gas pressure from shot to shot due to the gas port being anchored in perfect alignment by these modifications. Taking this to the final steps, one would knurl or punch peen the oprod guide buttress to a NM fitment and to perfectly center the oprod tube to the gas piston. And lastly, Tig weld untize the gas cylinder and band.... which is actually the first step in accurizing the gas system and optimizing the rifle's performance overall.
 
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As usual 45ACPKING, thanks for the thorough explanation ( I hope you are aware how much you've helped me with your advice on this forum, whether directly or indirectly, since i first joined. I actually was referring to comments you made on a previous thread but i didnt want to call on you specifically demanding help lol! But you came through anyway!

Im going to consider my options now and see if i should bother taking a crack at it.
 
So just for a touch more detail...

Do I strike it on the angled/ flared/ flange portion at the rear of the buttress? Basically just pushing it forward ever so slightly? (Sorry for my poor knowledge of the terminology)

And what part of the barrel should i rest on? Just the opposite side of the buttress from where I'm hitting?

I'm probably way over thinking it.

As for unitizing the gas system, as soon as I can have it done i will take care of that if needed. I have on old friend who is a welder but I haven't spoken to him in quite some time. Might be a good opportunity to reunite!
 
gnmontey said:
Seems to me shims would be easier and carry a lot less risk of messing things up.

M
Click to expand...

For sure it would be easier to shim it. It was a bit of a pain hunting down the shims. I only found one place in canada that has them. I even considered making some from shim stock.

But then i remembered reading about the peening and thought it might be worthwhile see what is involved in the procedure. I'm fairly confident in my abilities but I think I'd rather see how its done before attempting it myself.

I am going to try a few regular gas locks first to see if i can get it right without shimming or peening anything. Its getting a scope so i wont need the gas lock front sight at the moment anyway.

We shall see how it goes.
 
gnmontey said:
Seems to me shims would be easier and carry a lot less risk of messing things up.

M
Click to expand...

my take on shims is it really depends on the material you are using for shims. If you could find a piece of titanium or heck even hardened carbon steel, turn it on a lathe to the exact dimensions needed to shim for gas port alignment.... that would work great.
problem is most shims are stainless , a dissimilar metal for one, also it is more maleable and prone to failure in it's role after so many rounds. Second bogus thing about shims is they need to be stacked up to mix and match till the right fit is aquired.
That said, stainless shims are the popular choice.

peening the buttress forward is so simple.... and if you go too far is simply a job for a fine file to even out the edge.
C.308 .... you wanna roll the edge closest to the gas cylinder forward, so just catching the edge with the hammer. If I did it right in front of anyone.... the light bulb would go on hehehe
no one at my clinics had difficulties once they were shown.
Just roll the edge over, not the whole buttress.


For years i have watched everyone modding thier rifles, doing these little tweaks just because the sticky say so..... without even realizing why these procedures are done.
An accurate m14 .... and I don't mean one that shoots a nice tight group and then all goes to hell..... I mean a rifle that just shoots tight groups..... is a rifle that has mechanical repeatability in it's moving parts..... like a machine. forget the powder, forget the bullet ect ect ect.... focus on the mechanical moving parts and bring them all into perfect harmony. Then address your loads.

That repeatabilty starts at the gas system and how pushes back that oprod. The methods taught to me address the mechanical repeatabilty of the parts of the rifle that affect harmonics and thus accuracy. Shims have thier place..... but I don't use them as they are but a temporary thing and not a permanent solution to gas port alignment optimization.
I hope I'm making sense and not sounding like a windbag hahaha
 
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You're not sounding like a windbag at all.

Thanks for the clarification on the peening. Just the edge, got it. I kinda thought thats what you meant but i wanted to be sure. But then i got to thinking the edge might cause an uneven surface and ....I often over think these things. I dont want to butcher my rifle Haha

All im after is exactly what you describe. A rock solid consistent rifle. Im slowly gaining an understanding of how everything interacts. I learn best by seeing and doing so sometimes when things are described to me in written form i like to make sure i understand what is being said. Ive learned a lot so far over the last little while and have had a blast coming home after a long day at the shop, and checking my bolt lug contact and tightening my oprod guide, etc.

I'm going to see about those gas locks, but at some point i will be giving this a try. I think I have a craving for another long barreled m305...
 
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