I worked up some loads with the Berry's Superior Plated Round Shoulder 350gr, using HS-6, and CCI350 primers.
Shooting from a 10.5" 1/14 Gibbz Arms G4 Non Reciprocating Side Charging Billet Aluminum Receiver, on a Franklin Armory Libertas BFS lower with carbine buffer tube assy. Suppressed with a Rugged Obsidian 45, using their fixed mount adapter - all measurements in the full-length configuration.
Still to early to give final info (I'm actually loading up for another set of ladders tonight).
Ranged from 13.5gr to 15.5gr of powder (which is, for me, an uncomfortably low case load volume at ~30-35%). Everything cycled properly, including slide-lock / BHO. The 15.0 and 15.5 ran a little hot, with a bit of a twang in the buffer/spring. Groups were consistent - don't mind that groups II and III are lower than IIII and V, I was adjusting my optic at the same time. (and I know the Roman Numeral system; my marking technique is my own).
Second trip with 14.4, 14.6, and 14.8grs. I had two slam-fires, 1 in 7 rounds of the 14.6 and 14.8 loads - but that seemed to be a primer depth issue. Though I'll obviously be carefully monitoring that issue. Was firing offhand, focused on function, so groups aren't indicative of anything other than my patience - hence no pics.
No chrono at my range, but did have a dB meter - and the 15.0 and 15.5 both seemed to crack into supersonic at 5,500' of elevation (indoor range, 70 degrees / probably 40% humidity).
When things stayed subsonic, was getting 91-104dB with measurements taken ~2 ft left of the lower receiver, and in the high 80's 1m behind the shooter. Even what I perceived to be supersonic was only registering around 109-112 dB.
Now I just need to get my can outta jail, so that I can start running these over a chrono on my property (without pissing off the neighbors).
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