Thanks SD. I'm planning to break it down this weekend. (Looks like I'll be shoveling snow between tomorrow than then.) Anyway, the Carlson extender naturally came with a longer spring, so I've already covered the replacement-spring angle while I had the extender on. Didn't fix. So I removed the extender, just to start eliminating variables. No other mods, except like I said above I've removed the plug/limiter. It's just so weird. I've tried loading 2 shells, 3 shells, and 4 shells, and regardless of how many I load it consistently identifies the last shell and stops it from exiting the magazine. Bloody strange. I think the damn thing's haunted. --Dave