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Discussion Starter · #1 · (Edited)
EDIT: Far as I can tell it's the head space. The gunsmith got the barrel tight and called it good. I compared the chambered depth of the shells in the FN to the depth of the shells in my M1A1. A 308 is a 308? the case on the FN sticks out .+010 maybe more.
Conclusion the rifle was put together wrong. Will start new post on FN head space
The rifle cycles fine manually. The rifle fires fine, very very accurate. There is very little recoil. The gas tube is set on 4, shouldn't it be around 7? Before you get any farther: The copper shell's neck and shoulder angle profile are different than the Winchester 308
The neck on the copper round is what is expanding and jamming the shell in the chamber. The shoulder angle appears steeper and the neck appears shorter. Before I condemn the HB FN I am going to try the Brass ( I didn't have any with me) in FN and the copper in my Norinco M1A1
I was using a copper shell 308 stamp C J 93, the round is jammed into the chamber after it is fired. They both sit in the chamber the same way and appear to have the same amount of shell sticking out. To extract the shell the charging handle has to be hit hard, but it pulls the empty and ejects it.. The spent case has no marks on it, but the full length of the neck has black scrape smudges on it, (grease scrapes?). The shell opening has an ID of at least 308+. I can fit a bullet into it with very little resistance. The fired copper shell will no longer fit into the chamber all the way, it sticks out about, well the length of the neck. It has expanded too much to fit again.
**The rifle had a loose barrel. A gunsmith tightened the barrel and I see that he added a shim between the barrel and recv'r to take up the slack. I am now wondering about the head space. The upper was returned by the smith as fixed, the lower is/was considered a parts lower.
Help opinions advice? Thanks
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