Loads that cycle a 10.5 AR...

[steezo757]

I've been lurking around here for a while. Well yesterday, I pulled the trigger. I ordered a 10.5" Noveske barrel (.300 Fireball/Whisper) from Grant.

I've see that everyone has great results with SMK higher grain bullets (200, 220 and 240). I'll definitely have some SMK in my stash, but I like to shoot often and am looking for a more cost effective bullet accompanied with some reliable load data options.

For those that have played around with smaller grain bullets, which ones worked for you?

ETA: Looking for subsonic loads

[pug]

You didn't mention subsonic or supersonic loads but I was shooting my 10" AR pistol yesterday with supersonic loads using 155gr SMK and 165gr SGK bullets sitting on 14gr of N110. For subsonic in the pistol it will depend on the size of the gas port but usually it takes at least a 180gr bullet and around 8.5gr of powder to make it cycle. As you can see I'm not stating any particular sub load because it depends on how they make the barrel.

[steezo757]

Thanks for the reply.

Well I received the barrel last week. The gas port of the Noveske barrel measured to be 0.0875". BTW, I'm trying to load for subsonic only.

I took it out on Sat with some promising results. 12.3gr of ACCR 2015 behind a SMK 220gr cycled, grouped well @ 50yds, did not keyhole and held the bolt back on the last round.

As for the 180gr Remington Bullets, I put 7.6grs of ACCUR NO. 9 behind it and the action did not cycle. There was no keyholing at 50yds and they grouped well, but the impact was approx 4 inches lower than the SMK above.

I need to invest in a chronograph so I can tweek them into the 1025-1050 fps range.