Well, I fired the thing at the shoot in WV. This thing is a pussycat. It's relatively quiet compared to any of the rifles that were there (except for one very special one). It's quieter than any of my 1911 or any of the other handguns that folks had at the shoot.
Recoil is hardly noticeable, and the action is smooth and quick. Actually, it was too quick...
I started off with single rounds fed from the mag to test the feeding and disconnector. The bolt functions perfectly with the slightly modified magazine. Rounds are stripped cleanly, the stripper lug doesn't make contact with any part of the magazine, the disconnector resets perfectly, and the double hook trigger is very smooth.
When I loaded more than one round I started having problems with case ejection. The carrier would cycle back and slam onto the case before it even made it out of the receiver. was watching the action cycle when I was shooting. The empty would do a 180 and the carrier would slam closed on it and jam. We ground a little off the top trunnion lug (one I hadn't figured needed any milling), and thinned out the recoil buffer. After this, the action seemed to cycle a little slower but not enough. It was still jamming.
When the cases did eject, they didn't go too far. When I cycled the action by hand, the cases would only go a foot or so out of the ejection port. The ejector was a little long, so we trimmed it down a bit. This helped a little with distance, but the damn thing still jammed. I finally took the extractor out and was going to consider trimming it, but there isn't a whole lot there to begin with. The extractor was really tight. I thought maybe it might not be releasing the lip of the case really well, so I cut almost one full loop off the extractor spring. This lightened up the extractor a little bit. I didn't get a chance to test it after that. When I cycle the action quickly by hand, the cases now fly out 3 or 4 feet. I hope this takes care of the problem.
I won't be able to test it again until next weekend. If it still has problems, I'm going to install brand new recoil and hammer springs. The new springs should be stiffer than the used ones, and this should help slow down the carrier. If that still doesn't work, I'm going to replace the gas piston with a short length of solid rod. Then I'll install a guide rod and try a recoil spring from a Thompson M1A1. The distance traveled by my carrier is very close to that of the Thompson. The ejector spacing is also very close. If that doesn't work, I may have to resort to 1911 recoil springs since they are available from 7 to 28 pounds of recoil weight.
This project was a LOT of fun to build. It's fun to shoot, but I just need to work out a couple little bugs. When I build another one, there's only a couple changes I'll make. I'll cover those in another post.
I know there should be pictures, but I was too busy shooting the thing and trying to fix the ejection problem. Hopefully one of the other folks from the shoot has a pic.