[sigfan001]

I have a Sig P938. It works fine, in reality no problems with it, but there's an issue in which when I use the 7-round magazine and I rack one round with the slide, it scrapes the brass on the casing and a little bit into the bullet. I plan to save all my brass casings for future reloading so you can see how this is an issue for me. Can anyone illustrate what sections of the slide could be causing this and what part I would need to file down a bit to prevent this from happening?

 

[sigfan001]

I cleaned the slide hoping to catch where it was rubbing by looking at the deposited brass and ended up with this. It seems to be rubbing up on the center, a ball in the middle (not sure what this part is called), and a bit in front of that. I attached a picture with all the parts of question circled in red.

Would it be safe to file just a bit and polish the flat surfaces? What could I do about the ball part that is also scraping on the brass? Would sig take this in for gunsmithing repair under warranty since it's not really a malfunction? Or what advice would you guys give?

 

[Malicious Compliance]

I don't see this as a problem or anything which would cause me concern. You don't mention how many rounds you have run through the gun, but I would never touch any part of any of my firearms with a file. The brass deposits you highlight in the photo are not the area I would suspect as the culprit. They are too wide, in my opinion, to be the cause of the scratch. Why not put a dot with a marker on the side of the top round in the magazine, centered between the feedlips of the magazine, to help determine the location of the source of the scratch? If you still feel compelled to polish parts of the gun, get some 600 grit wet/dry sand paper or finer, and polish with some fine oil as a lubricant. Neither dremels nor files touch my weapons, especially in working areas.

 

[sigfan001]

I've only fired about 5 rounds through it. I am 100% sure those sections are the culprit. Before I cleaned it, it had those same marks, so I wiped it clean, marked a line with a marker on the top round, and on the opposite side so I could tell up from down, and racked it again. When I ejected the round, it had another scratch right on top of where I marked it with a marker, and the slide had brass deposits in those circled areas where there wasn't any before.

I'll try the sandpaper approach then.

 

[ThnkFrst]

The ball that you are referring to is intended to depress the follower as the slide recoils so the casing from the last round in the mag ejects cleanly.

If it has a burr on it, I might touch it with some fine emery paper but I wouldn't file it flat. I don't see the scrape on the round to be an issue though.