I'm going to have to agree with ToddG on this. When it comes to short barrels, the ballistics of 9mm and .40 are quite good because 9mm and .40 loads are optimized for 4" barrels.
OK, sorry. Didn't mean to start a ballistics debate. I forgot where I saw the data I was referring to, anyway. I saw a table or a comment on another forum (Internet comments are always correct, aren't they?
) that seemed to imply the 40 was better for short barrels due to its higher energy. I can't retrieve that data now, so it's really irrelevant.
Todd, I agree. I've probably reverted back to my old grip. I wouldn't mind taking multiple lessons until I really get the "correct" grip muscle memory. However, David is an hour and a half from me, so that's just not a practical solution. I haven't had much luck finding any local instructors who are proficient with the M&P.
Bottom line: I know my grip sucks, but it's not like I haven't been trying to fix it. But if I can't get keep the correct grip when I'm concentrating on every shot, I'm a little worried about having the correct grip if I need to use the gun in a hurry at 2 AM some night. I guess I'm a little worried about the "interface" between me and this particular gun frame. If the "correct" grip is so counter-intuitive that I can't recreate it even a couple of weeks after a lesson, then maybe this isn't the right gun for me. I don't have time to shoot daily (or sometimes even weekly) like the pros do. I get to the range a lot, but if I need to practice my grip hours a day every day, then this isn't the right gun for me.
For what it's worth, David actually got me thinking about the 9mm. He's a big 9mm proponent, and his belief is that if the recoil of the 40 is what's making my thumb brush the slide lock, maybe I'll have better luck with the 9mm. He stated at one point during my conversations with him that the 40 is prone to more problems like this because of the amount of muzzle flip it generates compared to a 9mm. He recommended I at least seriously consider switching over to a 9mm. So I am consdiering it.
I don't want to tick anyone off and start a ballistics or caliber debate here. I prefer a bigger bullet, but reliability from a smaller one is probably more important than an intermittently dependable big one (and I'm solely talking about my interface with this particular gun, not a vague generality!)