Originally Posted by
gandog56
Took the AR to the range today. After warming up with about 50 rounds of .223, I pulled off the 5.56 upper and put on the .300 AAC Blackout upper. Only had forty rounds to fool with it and the only sights was a variable scope I had laying around. Fortunately I hit the paper first shot and it wasn't too far off. About 10 rounds put me dead nutz on at 50 yards. Moved it out to 100 yards but I didn't hit paper, was shooting high. I ran out of ammo before I got it totally zeroed in. Seems like a fun round, but the darned thing slam fired on me about 4 times in that 40 rounds. (all four times let loose two shots) Not sure what to do to fix it.