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Posted: 12/16/2014 10:53:23 PM EDT
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In another thread I mentioned that I had a few issues. I was thinking that it could come down to a headspace issue.
Upper is a PSA 18" Stainless .308 upper. When I went to the range for the first few score of rounds, I had a few failure to fires. On examination, it looked to be a light strike on the primer. With the rounds that were FF's, the charging handle was very hard to pull back to extract the round. It took both hands to pull back to remove the round. The primer had a light dimple on the round and when re-inserted for a second time all of the rounds fired. Total number of FF's was about 5 of 59 rounds. The 1 round of 60 that I didn't fire was dented when I let the bolt go on the empty chamber indicator (a zip tie in the case of this range). More details: Ammo was Federal 7.62x51 149 grain M80 Lake City ammo. The lower was a PSA lower with thier build kit. Only difference was the trigger group was from another PSA lower build kit that seemed to fit a bit better (less trigger movement). Not sure if the the hammer spring is tighter on the .308 lower build kit or not. Thoughts appreciated. |
| See if the bolt will close on a .308 "go" gauge. This should be your first easily done test. If it does, it could be a tight chamber or out of spec rounds (try different ammo). If you have a reloading headspace comparator, or Mo's gauge, you can alternatively measure your fired brass to verify headspace is within specs. |
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