Is copper fouling real?

In some particular firearms yes it is a problem

In a long range rifle, using ballpowder in low humidity, it seems plausible.
I haven't had it happen to me yet, where I see groups open up for no reason, then do a mild cleaning like normal, it doesn't help, then give the gun a really hard aggressive hate cleaning and then it's fine.

I only notice it in my 30.06 and military surplus rifles.

I never notice it in anything cause I shoot everything close range. Handguns or close range rifles like 30-30s. I can’t say it doesn’t exist though just because I don’t have issues with it.

My brother's Parker Hale in .270 copper fouled so badly he thought the barrel had been shot out. I instructed him on how to get the copper fouling out of it and told him to then go shoot a group. He did as instructed and the accuracy returned to what it had previously been. Bro is much better about cleaning his rifles, now.

A buddy bought a used, mid 1960s Winchester Model 70 in 264 Win Mag. The bore had wide stripes of green. He scrubbed the bore with a lot of Sweet’s 7.62 copper remover and I think Hoppes #9. After many, many strokes the bore was clean enough that the 140 grain bullets made great, little groups. Problem solved.
I firmly believe all-copper bullets are more likely to shed more material in the bore than standard, lead core copper alloy jacketed bullets.
I put a lot of bullets through my 7mm Weatherby working up good loads. Almost all the rounds were with RL-26. It has anti-coppering agents and I believe they do a substantial job of keeping copper from building up. This does not mean cleaning the bore is no longer needed. Results may vary.

IMR uses Bismuth as a Decopper Fouling Eraser. I see no difference between 4350/4451 & 4166/4198 when I tried them. Still have to remove copper. The 4451/4166 seemed dirtier to me. The newer powder are double based powders, containing Nitroglycerin.

CFE223 uses Tin Dioxide as a Copper Fouling Eraser. Have not used it..

The military may benefit more from these additives, firing automatic weapons for 1000s of rounds, without cleaning.


Vihtavuori has photos of barrels at link. Can't find what they use.
https://www.vihtavuori.com/powders/vihtavuori-decoppering-agent/

Edit add- Carbon is more a problem for me then copper. Do use a bronze brush.

Butch's Boreshine isn't touted as a copper remover but it really pulls crud out of a bad bore when left to soak for awhile.
This patch came out of my Remington 783 30.06 after I was getting clean patches with Hoppes.

My 6 mm’s don’t foul badly after break in, larger calibers a bit more.

It can make a difference, it dosent ALWAYS make a difference, and many people simply dont use their rifles in a way to notice a difference.
I used quite a bit of cfe223 in my Grendel because much like 8208, it gave great fill and performance, but I honestly never worried if it was decoppering anything, the guns were cleaned completely after each session.
I have used most of the Endurons, and fouling elimination was never really a reason for me, simply wanted to see if the new "enhanced stability" powders worked well, and generally they do seem to, tho not usually as fast as other options.

High Plains said:

I firmly believe all-copper bullets are more likely to shed more material in the bore than standard, lead core copper alloy jacketed bullets.

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Absolutely, it's a problem! Especially with copper monolithic projectiles. I have a 243 bolt gun that, for many years, I used to shoot NRA High Power. My mainstay projectile was a Sierra Match King. I always cleaned the rifle and never thought anything of it. Five years ago, I repurposed that rifle to hunting and switched to Barnes TSX (lead-free, all copper projectiles) and got a rude awakening.

It is basically impossible to clean the rifle now. No amount of cleaning and no magic chemical will get it done. The patches always come out blue, indicating there is still copper in the barrel. The first 10 or so passes with the bore brush will produce actual copper shavings from the barrel. It's unbelievable.

In terms of accuracy, the rifle went from 1/4 MOA with a 60 grn SMK HPBT to 1-1/4 ish MOA with an 85 grn Barnes TSX HPBT. I can't definitively say that is the result of copper fouling; it may just be the difference in a match grade and hunting grade bullet, but there is definitely fouling. So much so that, if I wasn't so impressed by the destructive performance of the Barnes projectiles, I'd try something else.

Definitely real. I had some fouling on the lands of both my Glock Barrels, factory and KKM. Always used the nylon brush, and always looked great. Then I took some Youtube Advice and used a brass brush and afterwards noticed scratches. I was like ***?! Did my research and there is no way brass would scratch either barrel. Upon more YT advice I spun the brass brush on a drill, let me tell you, that barrel came out smooth, except for some obvious buildup on some of the lands. Upon further research, turns out fouling on the lands is copper. I only have ballistol, let it soak, and nothing. Was researching other products and methods.
Upon more YT advise, I took a smaller bore brush and wrapped copper wool around it. Did my thing on it and fouling still there. Used the drill again, still there. So I figured I need some solvent, which I dont have. So took my KKM barrel to the sink to wash and it came to my mind to let it sit in soap for a few and try the brush again. I **** you not I only stroke by hand a few times and took a peep, something was different. Blew out the water and the fouling was gone, the bore looked as good as new. Did the same procedure with the Glock barrel, hot damn, them some nice rifling.

Gunfu_Blaster.45 said:

Definitely real. I had some fouling on the lands of both my Glock Barrels, factory and KKM. Always used the nylon brush, and always looked great. Then I took some Youtube Advice and used a brass brush and afterwards noticed scratches. I was like ***?! Did my research and there is no way brass would scratch either barrel. Upon more YT advice I spun the brass brush on a drill, let me tell you, that barrel came out smooth, except for some obvious buildup on some of the lands. Upon further research, turns out fouling on the lands is copper. I only have ballistol, let it soak, and nothing. Was researching other products and methods.
Upon more YT advise, I took a smaller bore brush and wrapped copper wool around it. Did my thing on it and fouling still there. Used the drill again, still there. So I figured I need some solvent, which I dont have. So took my KKM barrel to the sink to wash and it came to my mind to let it sit in soap for a few and try the brush again. I **** you not I only stroke by hand a few times and took a peep, something was different. Blew out the water and the fouling was gone, the bore looked as good as new. Did the same procedure with the Glock barrel, hot damn, them some nice rifling.

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I mostly shoot solid copper monolithic rounds. I guess that's why I had the problem. Well, now I know, Dawn does it.

The bright green/blue patches coming out of my SAR-48 always told me it was real, after using Hoppe's Benchrest Copper Solvent.

Gunblue490 has a video on youtube where he talks about copper in the barrel not necessarily a bad thing. I have several guns I've been shooting for nearly 50 years (the same guns) using whatever cheap ammo on the shelf. Never any problem with copper. As a matter of fact I've never found any copper build up what so ever. Of course I clean my guns. Any build up of anything in a gun is more than likely a lack of cleaning. I have noticed that there are a lot of people that to ( lets say) exaggerate for some reason.

Like the other's said it's real.

How much of an issue it is depends on the individual barrel. I have Bartlein, Kreiger, Douglass and a couple PacNors that have been lapped and can (and do) go 100+ rds without a problem. I had a Rem M7 in .260 that would "foul out' in as little at 12rds, and cleaning it was a biatch.. the groups would open up to 1.5-2MOA when I got close to 15-20rds. It was one of my favorite rifles (in concept) so I had it re-barreled with another PacNor las year. I also tried Barnes solid copper bullets when they 1st came out, holy chit did they foul a bore.

It's also one of the reasons I follow a manufacturer's suggested break-in procedure. I've found that by doing so it helps reduce fouling over the long haul.

My method is to use Shooters Choice to remove the powder fouling, then Sweat's 7.62 to get after the copper. With the custom barrels, I usually just do 3 iterations with Sweat's:

All using a tight fitting Jag, with a Possum Hollow bore guide fit to rifle and chamber:

1. Couple wet patches, then dry patches with Shooters Choice, Dry well before using Sweat's.
2. Wet patch with Sweats, scrub for 1 minute, let sit for 5 minutes (3 iterations), then run a couple dry patches. 1st will be dark blue, subsequent will be lighter. Finally I'll run a patch or swab with CLP through, then dry 1 dry patch.

For the badly fouled guns, prior to cleaning I'll push a coupe of patches wet with Kroil to loosen things up. Then I use a nylon brush for the 1 minute of scrubbing, before going into my wet and dry patch routine.

My intent is not to remove all the copper, hence going to "light blue", but I don't want it building up. Patches and accuracy tell me how much cleaning is needed by barrel.

Jdague12 said:

Is copper fouling real or is it something we’re being coaxed into thinking is a problem?

I’m not saying it isn’t real. Just looking for some real opinions. I want to see who’s seeing “real” problems or is it something that just helps to keep barrels a little cleaner.

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I going to say that its real. I get blue stuff on a wet patch when I patch out a barrel and blue stuff on the rag that I place under the barrel after I wet the barrel and stand it up in the corner.

How it effects accuracy and how much you notice depends on how well your rifle shoots. You may see it in a custom benchrest rifle and never notice it in an off the shelf hunting rifle with a sporter weight barrel.

I try to clean my rifles often enough that clean-up is easy and not wait until I have to get aggressive with them.

D.B. Cooper said:

Absolutely, it's a problem! Especially with copper monolithic projectiles.

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Well said. My favorite .223 rifle was badly fouled from using the Barnes TSX bullets. Took two long sessions with Hoppes Benchrest to remove the fouling.

High Plains said:

A buddy bought a used, mid 1960s Winchester Model 70 in 264 Win Mag. The bore had wide stripes of green. He scrubbed the bore with a lot of Sweet’s 7.62 copper remover and I think Hoppes #9. After many, many strokes the bore was clean enough that the 140 grain bullets made great, little groups. Problem solved.
I firmly believe all-copper bullets are more likely to shed more material in the bore than standard, lead core copper alloy jacketed bullets.
I put a lot of bullets through my 7mm Weatherby working up good loads. Almost all the rounds were with RL-26. It has anti-coppering agents and I believe they do a substantial job of keeping copper from building up. This does not mean cleaning the bore is no longer needed. Results may vary.

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I saw the same thing the first year I worked for Les. He had just split off from Springfield Armory (1992 )and we were taking any work we could get. A guy brought in a pre-64 model 70 in 300 Winchester Magnum that he said was junk, as it couldn't hit the side of a barn from inside the barn. I looked down the bore and gagged. Nothing but green. After many sessions of cleaning It proved to be a very accurate. After the incident I realized I should have looked down the bare, gagged, and said " You're right, it's junk, I'll give ya $200 for it."

He probably would have taken it...!

tws3b2 said:

Any build up of anything in a gun is more than likely a lack of cleaning.

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I'm not certain I agree. My experiences have come after shooting 30-40 rounds, with a mild cleaning every 10 or so rounds. (experimenting with different hand loads, zeroing, etc.) I don't consider that a lack of care and maintenance.

alsaqr said:

Well said. My favorite .223 rifle was badly fouled from using the Barnes TSX bullets. Took two long sessions with Hoppes Benchrest to remove the fouling.

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I'm surprised the Hoppe's worked at all. I know it's a long standing tradition to use Hoppes, and I grew up with it, but I've totally abandoned it in favor of Birchwood Casey products and the Barnes copper remover. (And the Barnes copper remover isn't exactly stellar.)