Home Forums Hunting & Shooting Ask The Gunwriters cause of pitting in a rifle barrel

I have a 25 yr old Browning Low Wall 243 Win that has a lot of small pits from camber to crown in clumps and alone, lands and grove,(found thanks to a Bore Cam). Any ideas what caused them? It has been cleaned after every use with copper removers according directions. I am in Montana so humidity should not be a problem, besides never had rust on a cleaning patch. It shoots minute of antelope that part is OK, I just concerned that I did something wrong or just just had the luck to get a barrel with poor steel. Thanks.

CJL;
Good afternoon, I hope that you all are having a good weekend and all who matter to you are well.

Since you're in Montana, one thing that you might encounter that we north of the medicine line also do is hunting in cold weather.

When we bring our rifles in from hunting in the cold, they can sweat and under the right circumstances, in my experience some will rust.

One rifle I recall rusting rather quickly from sweating was a Browning BBR that I hunted with for decades. As you noted it didn't affect the accuracy as far as I could tell, but it surely did bug me!

It seemed to me that rifles which weren't fired in cold weather, that is to say if they were clean and lightly oiled as well, they didn't rust from sweating nearly as bad as if they'd been fired and not cleaned.

Just a thought from another cold weather hunter?

All the best to you all.

Dwayne

Tag

THAT is what happens when people obsessively need to clean the copper from their barrel.

.243 and 6mm bores take a beating...not surprised.

I've got an '06 that looks like that. My guess is it got that way after being brought in from the cold to a warm tent or house, condensation formed, and moisture did it's work. Good thing is, it's still a solid 3/4" shooter.

I have a Remington single shot 22 that is 90 years old by best I can tell…. inherited it in the 60’s from my grandfathers estate. When’s I got it the pitting was in the barrel then, is in the barrel now, shot little bug holes at 50 yards for me since. Nothing I can do about it except clean it after each firing and enjoy my every outing with it. I figure as long as the rifling is strong in a barrel and it shooting big holes, I won’t worry over it. I bet it was never cleaned when I got it 60 years ago.

What copper cleaner are you using?

I've purchased and borescoped brand new rifles right out of the box that have rust pits in them. Some of these rifles sit in storage wharehouses for years sometimes or in rusty freighters on the ocean for weeks. I know of one store that it is quite common to get rifles from them with rust, they store them in a damp basement. just leaving a gun in a case in your truck for a few days freezing and thawing is all it takes to get started.

Dyna Tech Bore conditioner helps those barrels a lot

I have a half fast theory that tiny water droplets adhering to the interior of a barrel of a high intensity cartridge when fired, can cause a rapid and violent microscopic steam explosion, creating a pit. No real evidence on a rifle bore...but direct and incontrovertible evidence on a diesel piledriver bore. A brand new piledriver cylinder completely ruined in a week of operation in rainy weather with an inadequate air intake (pulling water droplets in with each stroke). I installed a homemade dry air intake and the new cylinder, it still worked perfectly 6 months later in still rainy weather. Just a half baked theory but there remains the fact that when water molecules flash to steam, it's 1,600 times it's original volume. When that happens in a microsecond...that IS an explosion.

I always figured it makes more sense to not use a bore scope. If the rifle shoots well, what you don’t know won’t hurt you.

I think I can contribute here.

Scored a solid A in College Chemistry. Final paper was on Tetracyclene.....as I had acne as a young man. That antibiotic opened all sorts of doors, when it came to the young ladies.

Rust is the problem, when it comes to pitting.

Thank me later!

LOL

Please tell fester we said hey!

Californians.......of a feather.

Uncle fester?

Starting to like you, GRIZZ! Don't ruin it.

Uncle Bob Feilder Parkersburg West By God... "Eat your beans boy"

Use of a Borescope has proven to be the cause of barrel rust to many. Use at your own risk.

Some "copper solvents" will pit/etch barrels if left in the bore too long, or not totally neutralized after cleaning.

As others have pointed out already, the obsession over getting every speck of "copper fouling" out of the bore has harmed plenty of barrels, whether with such solvents or over-use of abrasive cleaners--which can leave the bore looking super-smooth through a bore-scope, but often makes it copper-foul quicker, resulting in even heavier fouling.

Also, as some of have suggested, Dyna Bore-Coat helps such bore a LOT, even when far more heavily pitted. Have applied to it several older rifles with barrels where the pits were obvious to the bare eye (no bore-scope required), whether caused by inadequate cleaning after shooting black powder, or mercuric primers with smokeless powder. Such primers were common until around in hunting ammunition, and longer in "surplus" military ammo. Had a Winchester Model 1894 in .25-35, made in 1898, for quite a while--and the bore was obviously primer-pitted, so much it wouldn't shoot cast bullets. After installing DBC it shot them pretty well....

I might have left cleaning solvents in too long. I have used about all brands over time. Maybe I should have used something to remove all the solvent, other than a dry patch. Too late now.