https://www.sigtalk.com/posts/6555606/

 

https://www.sigtalk.com/posts/6637010/

 

I’d try running a patch wetted with Sweets 7.62 or Barnes CR-10 through the bore a few times. It might be copper and not rust.

 

Well- just a wild guess here, but somehow it looks like???- 'moisture got to a dry spot'.

 

Comprehensive Corrosion Test: 46 Products Compared | Day At The Range

By: DIY_guy We all want to use goods quality products on our guns, bows, fishing gear, knives, autos, hunting and lake front gear and like you I?m not a fan of letting things get rust on them nor am I a fan of items wearing out prematurely. To protect my investment in gear, I began

dayattherange.com

 

As a new gun owner this is super comprehensive! I haven't bought a cleaning kit yet but now I know what performs the best out of 46 products in this comparison👍
EDIT:
I have to note WD 40 Specialist is not for gun barrels according to a Google search

 

https://www.sigtalk.com/posts/6341446/

 

This one is great info source

https://www.sigtalk.com/posts/6622718/

 

If it truly is rust, the best approach IMO is to use a piece copper chore boy pad wrapped around a brush wetted with a light oil and run it up and down the bore. That should remove the rust, but it may leave behind pitting in the bore. Unfortunately there is nothing you can do about that. I’d try the copper solvent first though in case it is just a bit of copper fouling. You will know immediately if that is the case as the patch will turn blue.

 

Another option is to try JB Bore paste. After cleaning a bore I always patch out with light oil, then before shooting, I patch dry.

 

Also try some new bore brushes brass or SS, they do wear out over time and have less contact with the bore. I wouldn't use the SS brushes as part of regular cleaning.

 

Borsesnake with a bit of CPL. Weird people having rust issues. I'm in WA state where summers are.hot, and we get all 4 seasons and none of my p365 or any pistols have, nor have got any rust ever. I shoot them all weekly x 200+ rounds and clean after every other range visit but still have had ZERO issues at all with barrel or surface rust. Even on my EDC which can get a little sweat on it from time to time in Summer.

I just have a clean microfiber cloth that I spray a very light mist of CLP on and then literally wipe down the exterior of all my pistols with basically an invisible coat of CPL so you can't really see it but it's there just as a very very fine protective layer of sorts but can barely feel to the touch, like super super light misting if even that much and it seems to do the trick to keep rest away. But yeah it's weird cuz I've literally never seen a single speck of rust on any of my guns even if I go a few weeks before touching them again, so you might start doing that. It doesn't take much at all just to invisible wipe down so it just leaves it tiny little trays on the exterior and it will keep rusting from that happening, as far as barrel goes I shoot the hell out of mine and just snake bore them every couple trips with a little CPL and again, zero rest ever.

Patch dry any barrels before range trips is also a recommended task but while sitting, get some good super light coat of oil in them. I'd not use the WD 40 stuff. Have read it's not all that great even though it's supposed to be. I have CPL for all cleaning and super late coating if they're going to sit for a while and then I drive patch it and wipe it all off before going to the rain and apply a little bit of blue Gun oil to the sliding parts just with my finger so there's no dripping or anything that's too wet so to speak where it shouldn't be and I've been doing it this way for 5 years at least on most guns and ever since new on the guns that are only like a year or two old like my two p365s and my 226 X5

 

I was always told the last cleaning patch going through has a drop of oil on it and you just verify a slight sheen inside the barrel.

I have one question. It takes under a minute to remove the slide and the barrel from the slide. Why would anyone use a boresnake at that point? You do a better job with a pistol cleaning rod. This is a 3.7 (XL) or 3.1 inch barrel. Longest is if you have a threaded XL barrel at 4.4”

just asking

 

I put around 1500 rounds a week thru my P365 xl macro and use, sigs cleaning kit. I’ve never seen any rust in my barrel. You can. Try any high quality clean solution made for barrels or give this one a try. SPEC1 - COMBO PACK, 2OZ LUBRICANT, BORE SOLVENT, FIREARM DEGREASER.

 

That barrel looks to need cleaned and oil patched... I havnt had any issues with any of my sigs, what are you cleaning the barrel with after solvent? Def need an oil patch because solvent removes fouling and oils

 

Oil patch it

 

Can you live without the gun for a while? If you can, I would test Sig's new warranty and send the barrel back to Sig for replacement.

 

Try Barkeepers Friend. It is used to remove rust from stainless steel sinks, etc. It works really well on light rust.

But be careful with it, as it will also remove bluing.

 

Aren’t SIG barrels blued?

 

Bar Keepers Friend would be my last choice over all the suggestions mentioned above.

Don't get me wrong, I love Bar Keepers Friend powder for removing rust stains and odor from nonferrous metals plastic and rubber. That powder when mixed with water is the only thing that I have seen remove cigarette odor from plastic and rubber.

 

It’s not a precision target pistol, swab the barrel with some oil and move on to the next crisis.

 

After you get it cleaned up use a VCI bag for storage. Do a little reading before you use it, but that plastic bag your weapon came wrapped in was a VCI bag most likely. The VCI bags are inexpensive and widely available, and come various sizes. I would recommend those especially if you don't have temp/humidity control in your safe. I use them for long term storage of weapons even in the safe with environmental control.

 

Also try some new bore brushes brass or SS, they do wear out over time and have less contact with the bore. I wouldn't use the SS brushes as part of regular cleaning.

View attachment 679947
View attachment 679946
Hello,

I own a SIG P365 XL and alternate carrying it with another pistol of comparable size from a different manufacturer on a monthly basis. Before storing the P365XL each time, I inspect it. While preparing to put the P365XL in the safe today I noticed what appears to be rust inside the barrel. I have not experienced this issue with my other carry pistol.

I performed several bore brush runs with solvent, but the spot remains. There is no visible rust anywhere else on the pistol, and the rust is limited to the interior of the barrel.

Please see attached photos.

I’d appreciate your guidance and look forward to your recommended course of action.

You say you carry on a "monthly" basis and inspect before storing?
Do you mean before you rotate the firearm EDC you inspect it, meaning only monthly?

A lot depends on the climate and environment you dwell.
(If you're in a desert arid or humid state such as Arizona / Florida )

In ⬆ cases I recommend you inspect them twice a week and rub them down / pull the barrel through (bore snake + CLP )

AND wipe over lightly the remainder of the firearm

 

Bore snake and BreakFree clp when you clean the gun. A couple drops, let it sit a minute or so and run the boresnake through it several times. Solvent removes lubrication. That’ll cause rust in the barrel in wet or humid environments.