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Posted: 12/14/2011 6:01:30 AM EDT
| Ran across a weird one. Rusty rifling in stainless barrel , bolt, carrier, & chamber have no corrosion, only slight carbon buildup. Only rusty parts were where the bullet had contact with barrel. Has anyone else seen this? |
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It's not copper.... Bore looked like a sewer pipe. I cleaned it out. Almost couldn't push a brush through it. A little J-B & Kroil cleaned it up pretty good. Still slightly hazy. Reminds me of the frosty look some surplus rifle bores have from being shot with corrosive ammo. Wonder it it was from rusted steel jacket fouling sticking to the bore....
Not my upper.... I was asked to have a look at it. |
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Interesting. I'm wondering if there's more going on here. Any idea on this barrel's round count? Is the rusty appearance uniform to the muzzle, mostly near muzzle, or mostly near the chamber?
Next thing I would try after the Kroil/paste would be some Patch-Out to see if the abrasives scuffed up the metal fouling so that it can interact with solvent. Sometimes successive layers of carbon and metal fouling have to be "unearthed". Sam |
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Not sure on round count... Not much wear on the bolt & carrier. Looked like less wear than my upper with less than 1k down the tube. Corrosion looked about the same from throat to muzzle.
Put a scope on it and fired it at 25yds. One smallish hole for 5 shots. May not have hurt it too bad. Need to stretch it out to know for sure. I don't have any patch-out. I'll try it if I can scrounge up some. |
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Quoted:
A "smallish" hole at 25 yards won't tell you anything. Actually it does.... Hole was a tight cloverleaf. I've tried the same thing with well worn surplus boltguns where they wouldn't hold 3" at the same distance. Barrels were pretty much toast before doing barrel CPR to them.... electrolytic barrel cleaning, lead lapping, handload experimentation, etc. Flat out worn out. |
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Older Wolf black box poly heads were not steel jacketed. Still have 10k or so with '04, 05, 06 date codes. Stuff was boxer primed and chronos very slow, like 2800 fps from a 20" bbl. Faster Wolf Mil Classic replaced Black Box and has had bimetal (plated steel jackets), berdan. Some time later Black box reappeared and projos are bimetal. Same goes for Tula and the various Bears.
Sam |
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When smokeless powders first became available shooters noticed they didn't foul as much as with black powder. Laziness and sales hype resulted in the needless loss of many barrels. Guess corrosive salt primer residue wasn't a thought for some.
When non-corrosive primers first became available shooters again bought the sales hype and thought they didn't need to clean the bores. Didn't work out so well. When McNamara's haste resulted in promulgation of a myth that M16s didn't need to be cleaned........well, you know what happened. When "stainless" steels became popular in firearms some shooters (esp. those lacking a background in metallurgy and chemistry) concluded "stainless" meant "impervious to any corrosion regardless of conditions or ammo". Wrong again. Seems like the latest rash (no pun intended) involves the belief that all ammo marked noncorrosive is equally noncorrosive. Not. Given the OP's description of a uniformly ugly bore I'm inclined to see this as a corrosion (vs steel jacket/friction/powder erosion) issue. Pics through a borescope would be a help. Sam |
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