I was an armorer in the army and I now am a gunsmith, i have messed with plenty of m9's the material used in the slide and frame are very low quality. i would see these brand new military m9's degrade significantly in about 1000 rounds. after another thousand i was replacing parts left and right and not like it was one part on all of them it was different in all of them. the barrel is the one thing consistant with all of them. The part of the slide where the barrel locks into when the slide is home wears away from the return to home. creating a gap. i have check with a caliper and this gap is quite noticable. it wont blow up but the more you shoot the less accuracy you will get also you begin to get feed problems.