I recently noticed that my USP45 Tactical has a small slide-to-frame play, from side to side. However, my USP9 expert has no such play at all. Is that a sign of weak recoil spring on my USP45T? How is the slide-frame fit on your USP45T? I only put approximately 800 rounds through my USP45T and I did not see any malfunction so far. Thank you.