I have had similar issues with mine as well with the mec-gar para mags. It jams once in a while and on occasion just won't feed the next round. It kind of half locks open on an empty mag as well. Also, and It is kind of weird, but the gun actually seems to have a different point of impact with these mags compared to the factory one. I didn't even know something like this was possible, so I will have to shoot some more and see if it is the gun or just me. I have the daswon extenders, but can't get many more rounds than what is specified by mec-gar. I haven't had much time to mess with that, but I'm guessing the follower just needs some work.