Pitting in Rifle Bore

[ICEMANLR]

Hey SH,

Was cleaning my rifle after a normal interval and noticed these marks inside the bore (apologize for the shotty pics), anyone know what these could be from. It’s a 6.5 PRC barrel with about 1000-1200 rounds on it.

 

[Frank Green]

What are you cleaning it with and how are you cleaning it?

How long after you shot it have you let the bore sit dirty? Do you clean the same day? Day or two later...have you ever put the gun away for an extended period of time dirty?

Did you leave a cleaner in the bore for any amount of time? If so...again what cleaner are you using and your cleaning method?

If those pits where never there before than I'll say it wasn't from when the barrel got made.

SS barrels will corrode...they will pit! They are not made out of surgical stainless etc....

You put it away dirty for X amount of time and depending where you live, the environment you store the gun in.... the bore can pit/corrode.

Later, Frank
Bartlein Barrels

 

[ICEMANLR]

Clean it with Hoppes every 200 or so rounds. I never leave cleaner in the bore for longer than 10 minutes before running patches through to dry it up. I left it dirty for a couple weeks about a month ago when I had to go to the field for some training. Could just leaving it dirty have caused something like this?

 

[supercorndogs]

If you run a patch right up behind the marks you will be able to see them better and get a better picture.

 

[ICEMANLR]

Another pic

 

[smoothy8500]

Come on, it's not tranny nipples at the White House, you can give us some clear pics of the barrel...

 

[ICEMANLR]

Here’s another.

 

[hafejd30]

Pretty bad

Did you shoot suppressed? Cans tend to hold moisture which could hold it there long enough to possibly do that if it sat for a while in right environment

 

[ICEMANLR]

Yeah I do, that could be the issue.

 

[BuildingConceptsllc]

Do you have a borescope?

 

[ICEMANLR]

No I don’t, will have to try and source one and take a look.

 

[BuildingConceptsllc]

The teslong borescope is cheap and it works very well. You can take pics very easily with it too and they are good pics if you adjust it right. I'd just get one of those.

 

[ICEMANLR]

Sounds good, I appreciate the recommendation I will take a look at one.

 

[Frank Green]

Clean it with Hoppes every 200 or so rounds. I never leave cleaner in the bore for longer than 10 minutes before running patches through to dry it up. I left it dirty for a couple weeks about a month ago when I had to go to the field for some training. Could just leaving it dirty have caused something like this?

Hoppe’s won’t hurt anything. I store all my barrels with a coat of Hoppe’s. Keeps cleaning and protects the bore as well. It just gets thick/gummy over time. So make sure you run a fresh wet patch down the bore and dry patch the bore and chamber before shooting it.

Yes leaving the bore dirty and putting it away for X amount of time and the bore can pit. I can not give an exact time frame. Every situation is different. Powders, primers, moisture content in the air, etc…

 

[Frank Green]

Attached is a page out of the M40a1 manual. Someone else posted this a few months back on a cleaning topic and I saved a copy.

Read the first sentence at the top of the page. The priming compounds etc... will cause rust/corrosion. So stainless steel barrels will not get that reddish type rust but they will/still can corrode/pit!

I see a handful of barrels every year where the shooter put the gun away dirty and corrosion happened. One guy not too long ago put several hundred rounds thru a 223 barrel (bolt gun). Put it away dirty. When he pulled it out and finally went to clean it... the whole face of the muzzle crown was pitted. He got lucky and nothing in the bore got pitted and the accuracy was still there.

One of the things I've always said is that a barrel will sweat and boom....here it is in black and white. Sorry for the squiggly yellow lines. Not sure where that came from.

Every time you fire the gun....when the bullet leaves the barrel it creates a vacuum and sucks in the outside air. Moisture etc... then put it away dirty and the bore is still sitting there in the humidity etc... and after x amount of time presto. Corrosion. All those chemicals, copper fouling, powder fouling the moisture are going to work on one another.

 

[supercorndogs]

And people question why pictures of big foot are always blurry.