I’m putting together an M14/M1A. Finally got my receiver (Armscorp), and after installing the barrel, I dropped in a SAAMI GO gauge (Forster 1.630) and the bolt won’t close. The bolt lug just starts into the receiver lug and stops. So I figure the headspacing is to small by at least 8 to 10 thousandths (I came to this conclusion after viewing page 68 of Walt Kuleck and Clint McKee’s “The M1 Garand Complete Assembly Guide”.

I’ve read Ekie’s post, and he lapped the bolt to increase headspace. But which area would you lap? The face or the lugs? Also at which point is there too much material to be removed for lapping to be a viable fix? I can see lapping to remove only 1 or 2 thousandths but in this case maybe I should try a finishing reamer inside the chamber?

I’m confident of my ability to perform both operations if I have to, just need a little advice on which is the best route. Reaming or lapping.

Thanks.

What kind of BBL are you using?

Quoted: What kind of BBL are you using?

Don't know the manufacturer Noname. It's the new .308 barrel that Numrich sells. It’s a lightweight style barrel and it has no markings on it. It appears to be a well made, but I have to admit, I was kind of disappointed that it wasn’t marked.

I take it it's not chrome lined. If this is the case the chamber just needs to be lengthened with a .308 finishing reamer.

Aftermarket BBL's come "short chambered" so after installation the headspace can be set.






The bolt was lapped (in that other thread) because  the chromed chamber (USGI BBL) would not allow reaming.

Quoted: I take it it's not chrome lined. If this is the case the chamber just needs to be lengthened with a .308 finishing reamer. Aftermarket BBL's come "short chambered" so after installation the headspace can be set.

No, it's not chromed lined. I've built Carbines and Garands before using used USGI barrels. So I wasn't aware that new barrels were short chambered.

The bolt was lapped (in that other thread) because  the chromed chamber (USGI BBL) would not allow reaming.

Ah, I was also aware that chromed barrels could not be reamed but I did not catch the fact that Ekie's barrel was chromed. Anywy, thanks for the help, it was just what I needed!!

Ah, I was also aware that chromed barrels could not be reamed but I did not catch the fact that Ekie's barrel was chromed. Anywy, thanks for the help, it was just what I needed!!

You're welcome...!





Also note as a "FYI", you can ream hardchromed chambers. It takes a carbide ream to do it-----------but since you're removing the chrome from the chamber and throat (maybe) area it kinda defeats the whole idea behind having a chromed lined BBL.

And the cost of a carbide .308 ream would be a religious experience...