Took mine out to test function the other day. I found it was jamming regularly. If you slowly pushed a shell out of the mg with your thumb you could see it would start to point down. Also it was hitting a bit of an edge on the barrel feed ramp. I disassembled the mag and I'm pretty sure the baseplate was installed backwards? I changed it and lightly dremeled/polished the feed ramp edge. I couldn't get it to jam after that in the shop. We'll see at the range.
Also, I assembled it without the spring assist and it felt weird without a release tab. Is this unsafe?