Can fouling hide pitting in a bore?

[killertom]

Hello,

I have a question regarding a pistol I bought two months ago. It was made in 1916, and I bought it believing it had a pretty good bore. It had a ring of pitting just forward of the chamber, but otherwise it looked fine, nice and shiny.
About three weeks ago I had to travel abroad, so I sprayed a generous amount of WD-40 in the barrel, wiped the pistol down with a rag soaked with WD-40, and placed the pistol in a steel storage box.
Fast forward to today. I looked down the bore, and it looked strange. I put a dry patch through it, and it came out with a smaller amount of greyish stuff. Now the barrel looks pitted for about 1-2 cm from the muzzle.

So I guess my question is, is it possible that decades of fouling have covered up the pits and that's why the bore looked better when I bought it, and letting it sit soaked with WD-40 (which as far as I know is a penetrant) loosened this fouling and revealed the pitting?

I find it highly unlikely that a bore could rust and develop pitting in less then three weeks if sprayed with WD-40...

So, all opinions are welcome!

Thanks!

Tom

 

[JohnBT]

Yes to the fouling. And a coating of lead in the bore can look really pretty, too.

 

[Daniel]

Yep.

It's good that you cleaned it though, as if you don't remove the surface gunk, it can continue to pit further.

 

[Alec]

As the others have stated, yes, it can make pitting hard to spot.

Also, I'd recommend using WD-40 for its intended purpose, instead of using it to prevent rusting. CLP, Eezox or something similar will work to keep rust at bay for storage.

 

[killertom]

Hi,

Thanks for the answers! The funny thing is I cleaned it with a bore cleaner after I got it, and it still looked fine. But I just simply can't believe that a bore can rust and develop pits in less than three weeks if sprayed with WD-40 and left in a not too humid environment... Maybe the fact that the bore was left soaking is what really loosened all the gunk...

Anyway, I'm done with WD-40 just to be on the safe side.

 

[Daniel]

WD-40 won't rust metal. It protects against corrosion and rust.

 

[Hardware]

But WD-40 dries up and leaves behind a hard, varnish like residue. It is best used for its intended purpose, water displacement.

 

[Ignition Override]

Don't numerous sellers at gun shows want you to believe that fouling only hides a very nice bore?

Either that is the case, or they assume that there are plenty of people who don't care whether the bore is in good condition.

If none of the above describes the most common reason for such indifference (regarding no more than four guns), what do you believe?

 

[BSA1]

Since the chambers in the cylinder are pitted it makes sense the barrel would be also.

 

[Daniel]

Hardware,

Yeah, it does, but said residue won't pose a problem. Just wipe it out before you shoot with a dry patch, and you're good to go.

O, and to add: in the OP's case, the WD-40 loosened the actual fouling from the bore, which revealed the pitting underneath. It's a common thing to see on military surplus bolts (on the actual bolt that is).

 

[Vaarok]

Ideally, with a bore that has some frost or pits, a certain amount of fouling can actually reduce speed of crap building up and improve accuracy somewhat, since the projectile isn't cheese-gratering down the pipe.