AlcoholicusMaximus
10-17-2010, 01:51 AM
I really thought I had it nailed down. M1S 10.5" AR15 in .300 whisper, gas port opened to .086, which cycles 220smk's subsonic flawlessly. Extensive load research led me to produce 300 or so 130gr Speer HPs, pushed by 18gr of W-296, which I have decided to replace with 125 Nos BT's due to too many FTF's with the Speers. Now, the 125's are hanging up, about one in 15 shots, usually the last, or second to last round in the mag, but not always. Both loads are having the same issue, which is that the tips are impacting the barrel outside the chamber at about 11 o'clock, and seems to happen only on the right side of the stack. I am using Magpul 20rd, CProducts 20rd, Bushmaster 10rd as well as Colt, OKAY & others.
I thought the short throat was causing me to seat to 2.107 with the BT's & the 130 Speers right at 2'', but the LC brass is just barely thin enough to jam into the chamber, and I realized that I have almost another .1'' to seat out before contacting the lands. I will test and report. I was getting about 2100fps.
I thought the short throat was causing me to seat to 2.107 with the BT's & the 130 Speers right at 2'', but the LC brass is just barely thin enough to jam into the chamber, and I realized that I have almost another .1'' to seat out before contacting the lands. I will test and report. I was getting about 2100fps.