I have the McCormicks and they worked great in my SA, but wouldn't drop free in my Nighthawk. After a little polishing and adjustment on the feed lips they are fine.
I brought this up with a well respected gunsmith on this site and his response was "only if you don't build the gun right" or something along those lines.
I've only had a few matches but I've taped every one. After each match, I'm try to concentrate on a thing or two that I need to improve and it's very rewarding to see the improvement in the next video. Taping the the better shooters is also a big help.
I just had my fourth match and I'm having the same issues. Smooth and steady is the way to go at this point. I've been videotaping my matches and I find that to be a big help. As long as I see improvement each time out, I'm happy.
BTW, Cool avatar.
I've been shooting for almost a year now and have just started shooting USPSA. I've have 3 matches under my belt and even though I see improvement with each match, I still have a long way to go. Having a site like this to draw info from has certainly been a big help.