Hmmmmmmm
Nice tips for the drawings of guns etc, good tips for beginners. I disagree with your recoil theory though, not all guns jerk upwards when shot.
For example, your smg has a stock, which speads out the recoil via the shoulder, and so the recoil should be very slight (if anything, moving backwards and forwards)
Im sure shotguns aswell dont just jerk into the air (most of them have stocks too...)
It differs from weapon to weapon... just something i think you should point out in your next tutorial :)
oooohhh and do something about animations for muzzle flashes... that could be handy :)