Generic Question: Barrel Pitting Issues

[Kurz]

Not exactly where this should be posted but I'm here the most...

At what point does exterior barrel pitting compromise barrel safety and strength? Recently, I purchased a rifle and all the metal looked excellent - including the bore. However, once I got it home, I took it apart and noticed some pretty bad pitting beneath the stock line. All the rust is gone now and you can see bare metal in all the pits. Thankfully, when the gun is together, not a single pit can be seen.

Personally, I don't think these flaws will compromise the barrel, but I'd like some opinions from others. This is a .30-'06 so I know there are some pretty darn high pressures generated.

[vintovka]

Ugly yes! but far from what I would call dangerous.

[Bloke_89]

Connect the dots and see what you get!

[Vaarok]

The rule of thumb I go by is pitting that's deeper than one third the thickness between outer surface and bore becomes cause for awareness and consideration. Short of that, no worries.

[Leon]

FWIW Hatcher's Notebook - Chapter VIII The Strength of Military rifles - discusses experiments in which the barrel of a Springfield 1903 was turned down at the chamber area on a lathe to 1/8 inch thickness and fired with service and proof rounds without damage. When the the barrel was turned to 1/16 inch thickness over the chamber, it safely fired three service rounds. A 75,000 PSI proof round blew out a piece ofthe barrel.

Absent other hidden metallurgical flaws, your barrel is probably fine for standard pressure ammunition.

[Vic]

It looks OK but on a side note you might want to reconsider what you consider to be an "excellent" rifle. Maybe a bit more examination is needed. All of that could not have been hidden under the wood line.

[Kurz]

Vic,

From what I could see while handling the rifle, all exposed metal appeared to be in very good condition... Certainly not mint but no noticeable pitting. Aside from taking the rifle apart, there was no way to detect what was hidden beneath the lower hand guard. Even when removing the handguard, the pitting is not evident.

[USMCsean]

You could do all the calculations to find the minimum diameter, but it would take you a long time and one thing that it is dependent on is the composition of the steel to get the proper numbers for the calculations. Ever taken classes that deal in dynamics, strength of materials, or mechanical design? If so, those classes let you know it's possible to determine this. But knowing the exact material composition is key.

[Vic]

Oh yes I see that now. That was a sneaky one.

[Tombstone]

I put 500 rds through this Type-53 before I removed the action from the wood and found major rust. T mic'ed one of the pits at .080". Still not half way through the barrel. Although I don't shoot it much, I have no reserves about taking it to the range.
Deep pitting around the chamber would concern a lot more though.

[USMCsean]

That pitting does not look bad enough to warrant being afraid, atleast not to me. I've seen a lot worse and people still shoot them. If you think about it, the stampings on the barrel are probably deeper than that pitting.

[USMCsean]

I put 500 rds through this Type-53 before I removed the action from the wood and found major rust. T mic'ed one of the pits at .080". Still not half way through the barrel. Although I don't shoot it much, I have no reserves about taking it to the range.
Deep pitting around the chamber would concern a lot more though.

Wow.... .o8o would get me scared. That's some deep stuff!

[Kurz]

That pitting does not look bad enough to warrant being afraid, atleast not to me. I've seen a lot worse and people still shoot them. If you think about it, the stampings on the barrel are probably deeper than that pitting.

USMCSean,

Good point... There is an 'X' stamp on the barrel (no idea of the meaning) and it does appear deeper than any of the pits. I think one of the pics shows the 'X.'

Funny thing about all this is the bore is in very good condition - shows some wear but remains bright with absolutely no pitting.

[vintovka]

Hiding pitting under the wood is common trick to be aware of . What got me once was a "High Priced" milsurp that had the deepest, crudest, dovetail cut into the barrel at a crucial spot. No way to check under the wood at purchase and no recourse. Good reason to always completely disassemble and inspect new aquisions before firing.