Please. Nearly all movies have completely wrong sounds for the guns. The gun noises are all dropped in during post-production using canned soundFX. Rarely are those FX labeled anything better than "Machinegun - 10 seconds." The sound guys have NO CLUE, and just put in whatever "feels right". Sometimes, the director will ask for changes to enhance a certain mood or whatever, but that's about it.
That's why I was STUNNED when I saw
Heat in the theater, and they had clearly recorded the actual weapons being fired on the actual locations, and used the actual sounds in most scenes. Director Michael Mann (of Miami Vice fame, among others) really wanted to get the gun sounds right, and, WOW, he sure did. Saving Private Ryan, Black Hawk Down, and We Were Soldiers have all helped raise the standards in this area, after those standards being so low for sooooo long.
It's enough to make you puke up your Ju-Ju Bees when you see/hear a Bruckheimer film...
-Troy