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  #1  
Old 02-06-2021, 07:41 PM
krdomingue krdomingue is offline
 
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Default Commercial barrel turns past index point before getting tight.

I have commercial barrel that was reportedly taken of an SA Inc M1A rifle that I am attempting to put onto a Bula receiver. The barrel turns about a 1/4 inch past the index point before it starts get tight. Is there a proven method to shim the barrel or is it a lost cause?
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  #2  
Old 02-06-2021, 07:50 PM
nf1e nf1e is offline
 
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You can roll the shoulder. Compress the barrel metal that contacts the front of the receiver to tighten it up. Very simple process and no need for shims.
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  #3  
Old 02-06-2021, 08:17 PM
krdomingue krdomingue is offline
 
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Quote:
Originally Posted by nf1e View Post
You can roll the shoulder. Compress the barrel metal that contacts the front of the receiver to tighten it up. Very simple process and no need for shims.
I will try that. Thanks
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Old 02-07-2021, 05:52 AM
gjungle56 gjungle56 is offline
 
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If me, I would give barrel a quick head space check at approximate index. If I figured right it'll take a roll equaling about .008 just to get to hand tight index and then yet more for the barrel to be tight. I've always wondered what is the objection to a shim? After all, the Rem 700 recoil shoulder is actually a shim. As a tool maker, I shimmed chipped carbide die parts all the time, standard op procedure, with no ill affect. I have shimmed barrels that had out of true shoulders, and then cut true, for proper index. with no ill affect. I do make the shim out of the hardened blue stock.
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  #5  
Old 02-07-2021, 12:27 PM
krdomingue krdomingue is offline
 
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Quote:
Originally Posted by gjungle56 View Post
If me, I would give barrel a quick head space check at approximate index. If I figured right it'll take a roll equaling about .008 just to get to hand tight index and then yet more for the barrel to be tight. I've always wondered what is the objection to a shim? After all, the Rem 700 recoil shoulder is actually a shim. As a tool maker, I shimmed chipped carbide die parts all the time, standard op procedure, with no ill affect. I have shimmed barrels that had out of true shoulders, and then cut true, for proper index. with no ill affect. I do make the shim out of the hardened blue stock.
I have no objection to using a shim other than making one is beyond my knowledge/capability. I would need to find a commercially available shim that would fit.
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  #6  
Old 02-08-2021, 10:25 PM
jmm jmm is offline
 
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Doesn't adding a shim increase the headspace on a previously reamed chamber?
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  #7  
Old 02-08-2021, 10:30 PM
gjungle56 gjungle56 is offline
 
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Yes it will, so will rolling shoulder
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  #8  
Old 02-08-2021, 10:42 PM
4gun-drill 4gun-drill is offline
 
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Quote:
Originally Posted by gjungle56 View Post
Yes it will, so will rolling shoulder
No, it won’t. If the barrel is at TDC the headspace won’t change unless you go a full revolution one way or another.
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  #9  
Old 02-09-2021, 03:16 PM
Ted Brown Ted Brown is offline
 
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There is no correlation between various commercial receivers and commercial barrels that insure proper head space when switched.
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  #10  
Old 02-09-2021, 04:17 PM
krdomingue krdomingue is offline
 
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Quote:
Originally Posted by Ted Brown View Post
There is no correlation between various commercial receivers and commercial barrels that insure proper head space when switched.
I have gauges. I will check headspacing if I ever get the barrel on properly.
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