www.MG42.us

new barrel, NOS barrel extension-- can't get the barrel collar to match face with the extension, I have 0.10 inch gap between them. tried 4 times screwing and unscrewing the barrel, using antiseize on threads and a chain strap type vise grip tool on the barrel with thin piece off rubber over the barrel-- ever time, this is as deep I goes. never had reason to separate a barrel from extension, so I don't know what the threads are supposed to look like, meaning this new barrel is threaded shallow. the new barrel came with a kit I bought 5 years back, never planned on using it. off my topic here-- who makes theses new barrels and are they button pulled or hammer forged, I would'nt know the difference if you showed me? Ok, back to the former, this 0.10" gap is unacceptable, don't just spot weld it here because I can't pean it. didn't bother with head space, because every barrel and extension I've seen the faces match. GO or No Go on this. thanx for any advice.

Check head space to see if barrel threads are too shallow when bound up; and also check barrel dimensions to see if in spec. I can recommend a competent professional gunsmith here in Texas who can assist you. JR Houston Texas

thanks for the help, figured it out myself

Sooo what did you find?

ordered a P.O.S. used extension with just the stub poking out. removed the barrel stub and compared the thread count to my new barrel. as I had thought, the threads were cut to shallow. put the new barrel in the lathe and finished the threads. p--s poor quality control, must have been 4:15 on a Friday, last barrel for the day.

I remember recently encouraging someone to just pay the extra money and get an original barrel.

Considering that he was without your skills to be able to fix a screw up, he and I both agreed that it was a wise choice.

If it was easy, everybody would build a 42. It certainly separates the AR15 "builder" from the more serious and dedicated crowd. Atta boy.

lol glad someone out there has a lathe (I'll get one someday)

after being 11 months in, I'm getting closer to finishing, thanks for the encouragement jbaum