I'll try to keep this brief. 11.3" barrel with an Adams Arms Piston kit. Why piston? Because I'm a lefty and shooting with a silencer on a DI rifle plain sucks. What I've put below is over the course of 2 years.
When I started this project, Adams didn't have a .300ACC kit, so I tried their 5.56 kit with a lightweight carrier. With .195gr supersonic rounds, it worked ok, but only at full gas. Step up to 220gr subsonic and function is pretty awful. It will eject the spent case, but won't pickup the next round. Contacted Adams who suggested drilling out the gas port to .125". Did that and no real improvement. At this point, my mind is stuck on the weight of the system not being driven back. I order a lightweight, flat wind buffer spring. It comes months later. Swap it out and at full gas, some of the 220gr will pickup the next round, but nothing locks it open on empty. Contact Adams again, who now informs me of a .300ACC kit. I order the parts that are different and install. The new gas block has 5 settings, and only on full gas (and suppressed) will it pick-up the next round reliably.
This is where I am today. I really want to put a video camera on it and watch it in slow motion. Part of me is wondering if I need a heavier buffer or carrier to increase momentum and overcome the spring. The current buffer is 3.0oz. I know this is an odd duck, but anyone have any ideas? I want it to function with the 220gr loads without the silencer.
When I started this project, Adams didn't have a .300ACC kit, so I tried their 5.56 kit with a lightweight carrier. With .195gr supersonic rounds, it worked ok, but only at full gas. Step up to 220gr subsonic and function is pretty awful. It will eject the spent case, but won't pickup the next round. Contacted Adams who suggested drilling out the gas port to .125". Did that and no real improvement. At this point, my mind is stuck on the weight of the system not being driven back. I order a lightweight, flat wind buffer spring. It comes months later. Swap it out and at full gas, some of the 220gr will pickup the next round, but nothing locks it open on empty. Contact Adams again, who now informs me of a .300ACC kit. I order the parts that are different and install. The new gas block has 5 settings, and only on full gas (and suppressed) will it pick-up the next round reliably.
This is where I am today. I really want to put a video camera on it and watch it in slow motion. Part of me is wondering if I need a heavier buffer or carrier to increase momentum and overcome the spring. The current buffer is 3.0oz. I know this is an odd duck, but anyone have any ideas? I want it to function with the 220gr loads without the silencer.