to make mine as flat as it can be.....I trimmed the slide lock lever. mine is slide rack only as I dont want to miss the lever in a stressful situation. To answer ammo question and not sure 9mil has this issue...but the fatter/wider slugs like that is 45acp have a tendancy to kiss the lug on the slide stop. I dont have any issues with mine and I run a mix of old hydrashocks and some 124 G/Ds which are cone or tapered slugs.