Reindexing - overindexed barrel M305

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MartyK2500

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I have searched this quite a bit, seems like the real way is having a friend machinist roll back the shoulders with a certain angle (5 degrees?) and reinstall barrel.

I have seen on M14 forums people rolling them back with a pipe cutter but removing the cutting wheel and replace with a rolling wheel. Yes you back them up but with a 0 degree angle.
I have also found people than peen the shoulder at multiple places.

Do any of these homebrew methods work? Or will this be my donor receiver for Wolverines USGI parts kit?
 
They all work. Another method is to use a spacer ring cut from shim stock.

PS to Barney - Ram trucks eat Toyota trucks for breakfast :)
 
You are far better off making a washer and indexing the barrel that way. Remember, if you are unscrewing the barrel you are also increasing your headspace!

Scott
 
Yes I definately saw this comming (headspace)
Currently sitting at 1.643", how many thous can i lose in the process?
This specific rifle will only use brass 7.62 ammo as its not planned to have a US bolt put in this one
 
Never heard of the washer method, ill research it on other forums
Is it more reliable than peening long term?

Edit : Barney,even though im leeching info here and there, can't wait for a clinic within a few hours from Ottawa and learn this stuff live. Any plans for 2016 or will it go to 2017?
 
First thing I would do is turn off the barrel and turn it back on, bringing it to proper index. Remember that there is that ridiculous setscrew to deal with. See how much torque it takes to index. You may not need to mess with the shoulder if the over indexing is slight.
If necessary, the shoulder can be rolled, peened or a breeching washer installed. Rolling and peening upset the metal, when the barrel is torqued in, the metal is pushed back.
A breeching washer does not depend on upset. Personally, I would not use a very thin shim stock washer. I would machine the shoulder back, and install a breeching washer of substance. Like a Remington Model 700 recoil lug, or the breeching washer on a FN FAL.
Threads are 10 per inch. Easy to calculate longitudinal change. 5 degrees rotation is just over a thousandth of an inch.
 
MartyK2500 said:
I have searched this quite a bit, seems like the real way is having a friend machinist roll back the shoulders with a certain angle (5 degrees?) and reinstall barrel.

I have seen on M14 forums people rolling them back with a pipe cutter but removing the cutting wheel and replace with a rolling wheel. Yes you back them up but with a 0 degree angle.
I have also found people than peen the shoulder at multiple places.

Do any of these homebrew methods work? Or will this be my donor receiver for Wolverines USGI parts kit?
Click to expand...

TacticalTeacher said:
Yes..... :cool:
Click to expand...

As Barney has stated, all the above methods work.

tiriaq said:
First thing I would do is turn off the barrel and turn it back on, bringing it to proper index. Remember that there is that ridiculous setscrew to deal with. See how much torque it takes to index. You may not need to mess with the shoulder if the over indexing is slight.
If necessary, the shoulder can be rolled, peened or a breeching washer installed. Rolling and peening upset the metal, when the barrel is torqued in, the metal is pushed back.
A breeching washer does not depend on upset. Personally, I would not use a very thin shim stock washer. I would machine the shoulder back, and install a breeching washer of substance. Like a Remington Model 700 recoil lug, or the breeching washer on a FN FAL.
Threads are 10 per inch. Easy to calculate longitudinal change. 5 degrees rotation is just over a thousandth of an inch.
Click to expand...

Tiriaq is giving good advice here, if you were to add a "shim" or "washer" you don't want to just sandwich one in there, turn the barrel shoulder back and build a proper spacer.

When indexing the barrel, or installing a barrel, you want the barrel to become hand tight at no less than 15 degrees and no more than 30 degrees. You can then torque to TDC and be rest assured that the barrel isn't over torqued.

Many over indexed barrels, that I have seen, had galling on the receiver face due to the torque applied when being assembled. So that will also need to be touched up if it is present.
 
Thanks all, as always the battle rifle section is very ressourcefull!

Tiriaq, call it luck, or call it problem solved in 2013 batch.
I have 4x M305s, from 2013 serial, all 4, the screw went out well. With some resistance, with the correct bit and a bit of torq they all came loose, and we're not impossible to unscrew like stories i often hear about.

Edit : i might have missed a few notes on M14 tuning, what does TDC stand for?
 
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I have not measured precisely, using a NM flash hider, the front sight has to be far right for it to be usable. Almost no windage adjustment in rear sight, just a bit to compensate a bit more.
 
Thats why i use a national match FH to compare
On this one you also clearly see the pointy end of barrel feedramp, is off a few degrees from being perfectly down.
I know not a reference, but this combined to NM going crooked, it seems overindexed
 
Try and get to one of Tactical Teachers clinics and you can fix it yourself as well as go over the rest of your rifle.
He comes here to Petawawa quite often so its not too far from you .
 
We are already chatting via PM, we'll get things done!
For the moment this is not rushing, as i have 3 other norcs i'm thinkering with that have very nice index
 
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