devious169
Sharpshooter
So, I built my first 300blk upper, mega mkm upper with wilson combat 16'' recon barrel, wc flashhider,wc adjustable gasblock and tube( running wide open) , wc semi bcg and charging handle. I function tested this with remington premier match 125 gr. 20 rds for function and 220 rds for break in with interval cleanings. All rounds were flawless, but 25-30 dollars a box! I decided to reload. Wanting to start with a light bullet and loving hollow points , I went with 110 gr sierra hp varminters. only powder with similar burn rate to h110 or w296 I could find was imr 4227. Starting with my brass,is lc 09 and was formed on rcbs ar dies, trimmed to 1.363 ( per imr test data). My starting load was 17.6,18.0,18.4,and 18.8 grains x 5 rounds per. Accuracy with the 18.4 grain was phenomenal and the 18.8 was damn good too! Only one catch, not a damn one would lock my bolt back! I ran a full auto 11.4 oz. and a semi auto 10.9 oz carriers and the buffer (i assume is a carbine) 2.8 oz. Any suggestions would be greatly appreciated.