Thanks for providing this excellent forum. I have a serious problem with my S40. It is (was) my primary carry piece until it started misfiring last week at the range. I started having failures about every 3-4 rounds. I took it home, stripped and thoroughly cleaned it according to the wonderfully detailed tutorials on this site. In particular, I removed and cleaned the extractor and firing pin/channel. I also lubed it well (lightly) with tetra gun grease. I took it back to the range yesterday, and still had the problems. However, this time, I noticed that the misfires were caused by the slide not returning to battery. This occurred almost every other round or so. The variance ranged from about 1/16" to 1/8". If I manually pressed the slide forward, the gun would fire correctly. When I got home from the range, I started playing with the slide by hand, to see if it would stick. If I gently moved it out of battery about 1/8"-1/4", it would remain about 1/8" away from the fully closed position. I then disassembled the gun and looked for areas of wear or protrusions on which the slide might catch. In the center of the slide, beneath the firing pin channel, there is a pair of "rails" that contact the "catch" (#10 on the USASteyr schematic). At the rear end of these rails, right at the point where they bevel up into the slide proper, there are two wear marks. I ran my finger over those marks, and there is a barely perceptible protrusion that catches my finger. there is also a protrusion on either side of the rails, so that it appears as if the metal has been flattened and widened ever so slightly, like it has been deformed by the strike of a hammer. I suspect that this is the cause of my slide sticking. Now the question is, what should I do about it? Do I risk smoothing the rails out with a fine file or grinder (dremel), or is this a job for a smith? If either I or the smith screw it up, I think the whole slide is ruined. I have about 1500 rounds through this gun, and it has been very reliable. My only problems with it until now has been its tendency to fail to eject when I forget myself and limp-wrist the gun. When I pay attention and keep a firm grip, that does not happen. Please advise. If I can, I will try to post a picture or two. Thanks in advance.