I noticed recently that my Sistema has uneven wear near the muzzle on the left size if the slide as opposed to the right. I noticed that when looking straight down the barrel, the slide rides slightly to the left and kisses the side of the dust cover while the right side has a gap. Is this a common occurance that could have been present since day one or did something likely happen to damage the gun rendering it "permanently damaged"? It's the only 1911 I've owned so I'm not well educated on all the quirks and nuances that may accompany them.