Without naming any names yet, I purchased a slide and a lower receiver from two different manufactures. (I know, dumb). When both units arrived I placed the slide on the lower receiver, racked it, and pulled the trigger. It worked. But, upon the next attempt to cycle the action, the slide was unable to function to provide the necessary function to re cock the trigger. Then, it doesn't have enough play in it to remove the slide from frame. Not wanting to blame either manufacture, of a problem, what have I done, to cause this problem????? Right, i'm too stupid to use a clock. However I have owned several since 1984 and no problems. All were Glock only with no changes. Anyone have an idea on how to get the action to recycle please inform.