Coloring in barrel

odugrad · July 28, 2013, 06:59 PM

I have a question. What causes different colors in the inside of my SIG barrels? I have noticed that some are bright yellow, some are orange, some have a rust color, etc. Is this okay and normal?

I have a couple MK 25s and 226s. I clean after every trip to the range.

rduckwor · July 28, 2013, 07:19 PM

Could be the reaction of whatever you used to clean with residual lead and/or copper.

James K · July 28, 2013, 10:44 PM

Copper or brass wash from bullet jackets?

Jim

AndyWest · July 29, 2013, 02:11 AM

Could you post some pictures? What are you shooting through them?

odugrad · July 29, 2013, 07:32 AM

I can't get a good picture of it. I'm just shooting regular 9mm fmjs. I don't use any steel cased bullets. And it only seems to be on the MK25 models.

I look into the bore and everything seems fine other than the coloring. I went to the SIG website and a few other people mentioned it but no one had an answer. I thought there might be someone here who has experience with this.

JD0x0 · July 29, 2013, 10:39 AM

Sounds like copper fouling to me. but it'd be more useful if we had pictures.

"yellow, orange, rust color" pretty much describes the color of typical copper fouling. It is often mistaken for rust inside the barrel.

iamdb · July 29, 2013, 11:50 AM

run some hoppes through it and see if the patch comes out purple.

odugrad · July 29, 2013, 12:15 PM

Every time I run something through it (and I've tried most everything), the patch always comes out clean.

Is copper fouling extremely damaging?

James K · July 29, 2013, 12:31 PM

The amount of copper (actually gilding metal) fouling left by bullets is not enough to worry about. Ammonia will remove it, but may harm other parts of the gun (or you). A mild abrasive, like toothpaste, can also be used.

Myself? I don't worry about it.

Jim

odugrad · July 29, 2013, 02:43 PM

Also, would copper fouling take a long time to occur. I've only had the gun about 3-4 months. Maybe 1000 rounds.

JD0x0 · July 29, 2013, 03:38 PM

Quote:

Also, would copper fouling take a long time to occur. I've only had the gun about 3-4 months. Maybe 1000 rounds.

Sounds like it's time for a cleaning. Copper fouling can build fairly quickly. It depends on the rifling, the bore and the bullet. Tiny imperfections in the bore will catch the jacket material and deposit it in the bore. I've had a clean bore show copper streaking after 1 shot, which is fairly normal, unless you have some sort of chrome lined or polished bore. Once this fouling is in the bore, it will continue to build on top of itself, with each bullet that goes down the barrel. Allow it to build long enough and you could have accuracy problems, or worse.

Use a copper solvent which chelates the deposits and breaks them down, to be removed by a patch. How frequently you do this, is up to the shooter. I would recommend that you do it more often than every 1000 rounds. I make a habit of doing a thorough copper cleaning after every box.

July 28, 2013, 06:59 PM	#1
odugrad Senior Member Join Date: March 13, 2013 Location: The East Coast Posts: 477	Coloring in barrel I have a question. What causes different colors in the inside of my SIG barrels? I have noticed that some are bright yellow, some are orange, some have a rust color, etc. Is this okay and normal? I have a couple MK 25s and 226s. I clean after every trip to the range.

July 28, 2013, 07:19 PM	#2
rduckwor Senior Member Join Date: June 26, 2008 Location: L.A. - Lower Alabama Posts: 365	Could be the reaction of whatever you used to clean with residual lead and/or copper. __________________ RMD

July 29, 2013, 02:11 AM	#4
AndyWest Senior Member Join Date: October 14, 2011 Posts: 627	Could you post some pictures? What are you shooting through them? __________________ Shoot smart. Shoot S-Mart.

July 29, 2013, 11:50 AM	#7
iamdb Senior Member Join Date: March 13, 2011 Posts: 455	run some hoppes through it and see if the patch comes out purple. __________________ John 20:29 Jesus said to him, “Thomas, because you have seen Me, you have believed. Blessed are those who have not seen and yet have believed.”

July 28, 2013, 10:44 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Copper or brass wash from bullet jackets? Jim

July 29, 2013, 07:32 AM	#5
odugrad Senior Member Join Date: March 13, 2013 Location: The East Coast Posts: 477	I can't get a good picture of it. I'm just shooting regular 9mm fmjs. I don't use any steel cased bullets. And it only seems to be on the MK25 models. I look into the bore and everything seems fine other than the coloring. I went to the SIG website and a few other people mentioned it but no one had an answer. I thought there might be someone here who has experience with this.

July 29, 2013, 10:39 AM	#6
JD0x0 Senior Member Join Date: January 30, 2013 Posts: 1,037	Sounds like copper fouling to me. but it'd be more useful if we had pictures. "yellow, orange, rust color" pretty much describes the color of typical copper fouling. It is often mistaken for rust inside the barrel.

July 29, 2013, 12:15 PM	#8
odugrad Senior Member Join Date: March 13, 2013 Location: The East Coast Posts: 477	Every time I run something through it (and I've tried most everything), the patch always comes out clean. Is copper fouling extremely damaging?

July 29, 2013, 12:31 PM	#9
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	The amount of copper (actually gilding metal) fouling left by bullets is not enough to worry about. Ammonia will remove it, but may harm other parts of the gun (or you). A mild abrasive, like toothpaste, can also be used. Myself? I don't worry about it. Jim

July 29, 2013, 02:43 PM	#10
odugrad Senior Member Join Date: March 13, 2013 Location: The East Coast Posts: 477	Also, would copper fouling take a long time to occur. I've only had the gun about 3-4 months. Maybe 1000 rounds.