When (and IF) you get one, the first time you take it apart to clean it - GO SLOWLY !! Look over your manual as you go and take your time. There is a small (~1/4") piece of nylon that IIRC is called a "buffer".
It is very easy to lose this little piece.
Also, to fully load the magazine takes enough force to hurt your fingers and possibly dent the brass of the ammo. As I haven't shot mine much (yet), I haven't had any problems. Several people (other shooters as well as LGS employees) suggest only loading 25 rounds.