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I am trying to organize my CMP parts kit so when I have the cash I can get the build completed. I am on the fence about used GI bolts and barrels. I am wondering even if I do buy a good condition take off barrel, can an armorer have issues headspacing? Does a bolt reach a point where headspacing it to a barrel can be an issue? I would like to keep the rifle as GI as possible, but with the new LRB, and 7.62 bolts it may not be worth the extra money to fork out for USGI. Criterion barrels are more money, but if i get burned on a take off barrel I would lose a lot more than the extra cost. Anyone with good and bad experiences? Thanks.
 

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I can speak to only my experience. I had a LRB built using all TRW components, the bolt and barrel were USGI take offs from only God knows the five w’s to. Andy over at SEI built the rifle and reemed/bored the chamber to match up with our M118LR rounds. There is no peeling or any other side effects. The head space is right in the middle for US requirements. With a Leuplod MKIV scope she shoots 1” MOA out to 600 yds, ie a six round group in a 6 inch pattern at 600 yds. Ive hit a 26” by 26” steel target numerous times at 880 yds. This is from a rifle in a wood stock that is not bedded. So to answer your question, no there are no ill effects to using a used bolt and barrel if they aren’t shot out. Have measurements such as bore and chamber erosion given to you before you lay out the money.
 

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Good to go!

As long as the headspace and bbl timing are correct, run with it. When I gave Gus my receiver, bbl and bolt, he had a choice of a NIW TRW bolt or an old SA bolt. He immediately took the SA bolt and lapped it to the receiver.

The bbl was an HR takeoff.

All is good!

Bruce
 

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USGI verse?

If the USGI barrel is a take off there should be a "P" stamped in the barrel near the chamber along with the FSN and date, the "P" should have a punch mark inside the "P", this indicates that the barrel was installed and pressure tested after assembly. If the barrel threads time correct and the throat is 3 or below the barrel should be golden, as far as I can understand your question you are concerned that the barrel is somehow bad, if everything is as stated above the headspace of the barrel, not the bolt or receiver should be correct, I have never heard of a chrome barrel chamber growing.
The bolt depends on how much wear or lapping has been done to it, there are some minor variations to bolts and headspace that is why people who builds these make comments about reaching into their bolt bin and swapping bolts until they find one that fits the best and needs the least amount of work to headspace.
Your receiver probably has the most effect on how the build goes, if the thread fit is right (I have had receivers with threads so tight that barrels would not fit), if the barrel and receiver time correctly, if the receiver bridge is proper, if the locking lugs are where they belong, if the receiver face is square to the threads (I have seen receivers where the receiver face was not flat or perpendicular to the threaded hole) ect ect.
My experience is good USGI barrels fit up well, after market barrels not as easy (time and fit wise) it doesn't mean the after market barrels are good or bad just takes more time.

Jim
 
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