This is where I think a revolver comes in handy. Grab 3 or four rounds and load them by feel, spin the cylinder between loading them and close it up so that you have no idea which chambers have something in them. Start shooting as and Doc7 says watch your sights intently, if you can't say exactly where the sights were when the hammer dropped you didn't see the sights. Take time to analyze every shot. Get picky, I'm not talking on the bullseye or not, but where on the bullseye, center, 9:00 edge, center, 2:00 just off the edge, you get the idea. Probably best to precede your shooting session with a significant dry fire session just so you can fine tune taking these mental snapshots. You can do this with a semiauto pistol if you can come up with some dummy rounds. If your mag holds 7 count out four and throw in three dummys, mix em up and load by feel so you have no idea whats coming. I hope this helps, good luck.