I initially posted this on the ammo side since I thought it could be an issue with the ammo:
Problems with PrviHere's the run down:
I have a DPMS stripped lower with a Del-Ton A2 mid length upper kit. This is also a chromed lined barrel. I have used Federal Brown Box and PRVI 5.56. I have also used Wolf FMJ Black Box after the problems occurred to test various ammo.
I have used 3 USGI, 2 C Product and 3 PMag 20's and 3 PMag and 1 Bushmaster 30's for magazines.
This rifle has been fired 3 times and here are the problems:
Session 1:
-120 rounds of Federal Brown Box
-Cycled fine and excellent groupings
-Would not lock the bolt back when empty with any mags
Session 2:
-80 rounds of Federal Brown Box
-Cycled fine
-Would not lock the bolt back
Session 3:
60 rounds Federal Brown Box, 140 rounds PRVI 5.56 (what AIM is selling)
-Federal performed the same as previous 2 sessions
-PRVI performed the same as the Federal for the first 100 rounds
After those 100 rounds, I was getting FTE's, stovepipes and weak ejection (a few inches) with the PRVI. The upper was broken down and inspected. Nothing was noted yet this continued. It should also be noted that the gas rings are offset.
My friend was shooting Wolf FMJ Black Box and suggested I try them. They functioned flawlessly. I put 100 rounds down range, both slow aimed shots and rapid fire. No FTE's, no stovepipes and the bolt locked back when empty. The gun was not cleaned between the PRVI and Wolf.
This rifle has been thoroughly cleaned between each session. The chamber has been inspected with no apparent flaws. I also have the correct buffer installed.
This is a 5.56 chamber.
My question is this: Why would I have so many problems with 5.56 brass cased ammo yet function flawlessly with Wolf?
Logic would say the weaker pressure ammo would cause the problems. Could it be that the bolt is cycling too fast with the 5.56?
Another thing I noted is that the bolt, while able to move freely in the carrier, still seems to "stick" more that what I remember when qualifying in the military. I seem to remember the bolt on my M16A2 sliding very loosely in the carrier.