Bmt85 wrote:One member here was playing with heavier subs, and couldn't get his rifle to run with a midlength gas system.
Yes, that's me. BMT85 hit it on the head. If you aren't going heavy and sub you will have lots of dirty, unburned powder and no chance of cycling due to low chamber pressure. I had to push my heavy bullets on the order of 1400 fps to cycle reliably with a midgas system, and I'm starting to read pressure signs here. I do have much higher hope for the GC bullet I'm trying out though.
The people running non-cycling or bolt action light loads subsonic generally use a fast burning powder and a filler to keep the powder packed near the primer. Running a fast powder with low case capacity is NOT recommended.
All that said, these work ups are in anticipation of my suppressor which "should" be getting approved soon. I'm assuming this will help with cycling.