Just took my Sig P320F .45 ACP out of my range bag to put it in the safe and noticed this:



I presume it's from the brass. Has anybody seen this before?

Will they come off with Hoppe's or something, or is the slide finish permanently damaged? (Yeah, I know "It's a tool." But, still: That would annoy me.)

Pistol has all of about 300-400 rounds through it.

Some sort of odd ejection pattern, I would assume, provided that the slide couldn’t have come in contact with cases or cartridges in the bag or elsewhere. The second possibility would be my first suspicion because of the regular pattern of the marks. I cannot really think of how ejected cases would end up there, and especially not in a well-defined line.

Brass marks like that should be easy to remove with a copper-cutting solvent. Hoppe’s is a little mild in my experience, but might work; try that first. Put a bit on a bore cleaning patch or even a paper towel and rub. If Hoppe’s doesn’t work, there are many other options. Sweet’s 7.62 Solvent is one of the strongest, and Butch’s Bore Shine is a less aggressive option. There are, however, many others on the market.

The Nitron finish on SIG slides is extremely durable and therefore it’s very unlikely that the finish has been damaged in any way.

I'm sure the slide finish is not damaged, but it may take some time and effort to remove the brass marks. You probably need some copper removing bore solvent.

No doubt you will get many suggestions. Standby.

Since it was in your range bag, did you have a loaded magazine loaded with practice ammo (brass casings) or loose practice ammo (brass casings) in the same storage compartment as your P320? If so, it could've bumped against your P320's slide while in transit to and from the range. Brass transfers easily.

Very easy to remove, as sigfreund said. No damage to your slide at all, it appears.

I had the same thing happen to my brand new Ed Brown on it's virgin outing.

I let a few others shoot it before myself. One was new to handguns and limp wristed. That is how I believe I ended up with my marks.

I called Ed Brown for help and unfortunately they had no good suggestions. Although I was able to get rid of the brass marks this is what I found underneath.



so I've lived with them and mark it up to "aging" and will follow this thread to see what our wise pool of invisible friends have to say.

quote:

Originally posted by h2oys:
this is what I found underneath.

Oog! Based on the dings and the wear around the ejection port, it appears that the bluing is very soft. I would be astonished if anything similar happened with the slide of a P320.

Your experience, though, lends support to my belief that the marks on the OP’s slide had nothing to do with cases hitting the slide when the gun was fired. Yours are scattered and generally clustered around a central point—as we would expect from a random distribution, and nothing like the marks on the P320’s slide.

quote:

Originally posted by sigfreund:

quote:

Originally posted by h2oys:
this is what I found underneath.

Oog! Based on the dings and the wear around the ejection port, it appears that the bluing is very soft. I would be astonished if anything similar happened with the slide of a P320.

Your experience, though, lends support to my belief that the marks on the OP’s slide had nothing to do with cases hitting the slide when the gun was fired. Yours are scattered and generally clustered around a central point—as we would expect from a random distribution, and nothing like the marks on the P320’s slide.

I'm hoping the OP does not find what I found underneath my brass marks as does not the p320 have a nitron finish. My Brown has their G4 finish and it sure does show wear on all the high points from leather holster wear as well.

I show zero holster wear on my Sig fastback carry and my Sig p229.

Best of luck to the OP!

quote:

Originally posted by sigfreund:
Some sort of odd ejection pattern, I would assume, provided that the slide couldn’t have come in contact with cases or cartridges in the bag or elsewhere. The second possibility would be my first suspicion because of the regular pattern of the marks. I cannot really think of how ejected cases would end up there, and especially not in a well-defined line.

You called it. Went back down and checked. Sure enough: There was a piece of 9mm brass in the bottom of the pistol pocket in which the P320 had been stored.

To add insult to injury: There's a good chance it wasn't even my brass.

Normally I stash my handguns in those pockets right side up. This time slide down. Going forward I won't do that any more. I'll also make sure to thoroughly close the top of my range bag and check the pockets before stowing anything in them.

Good news is a bit of Hoppe's and some moderate elbow grease removed nearly all of it. What remains you have to look for to see, and I think actually is damage to the Nitron. So: Relatively painless lesson.

I do have some Shooter's Choice copper solvent. Maybe I'll try a bit of that.

h2oys: I'd have been bummed

Good that you discovered the cause.
Please let us know how the Shooter's Choice works.

Good news ensigmatic!

Yes I was bummed. I had hoped Brown would have considered a re-finish of the slide but the answer was no. The good news is she sure is a great shooter and now proudly wears her "war wounds".

quote:

Originally posted by sigfreund:
Please let us know how the Shooter's Choice works.

What remains doesn't look yellow-ish, so I suspect it's actually minor trivial damage to the Nitron. That being the case: I decided to just leave it be. Like I said: It's so insignificant that you wouldn't notice it unless you were looking for it--and even then probably not unless you knew it was there.