Hello, I am a "newbie" to GlockTalk but not to guns in general and pistols in particular. I am a big Glock fan, in part because of the ability to work on them myself. However, I have been trying to "build" an "Open" class Glock 22 Gen 4 pistol for use in USPSA/IPSC competition. I purchased an AimPoint APM-1R Scope Mount that fits new generation Glocks with the accessory rails. Well, I have had a heck of a time installing it to the pistol frame. The tolerances of the Aimpoint Rail and the Glocks Trigger pin holes and accessory rail slot are just a "tiny" bit off. Anyway, after much cussing and fussing I did get the rail mounted. However, since installing the rail, the slide is MUCH harder to cycle/rack than it was previously. It was already a little bit of a problem ever since I had a Fulcrum Trigger set put in but it is much worse now. I think that the pistol frame is slightly "torqued" due to the hole alignment issue and is causing friction on the slide/frame when it is cycled. The only other thing that I can think of is that the trigger pin is replaced with a threaded pin supplied by AimPoint to attach the rail to the frame. Is it possible that this pin is slightly too big? Anyway, I would appreciate any advice from those on this site. In addition, does anyone know of a good, actual gunsmith (not just an armorer) for Glocks?