Can irregularities in a bullet jacket harm a rifle barrel?

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FireInCairo

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I bought some Russian steel cased ammo in a local transaction last week. I didn't inspect the rounds, as I assumed they were typical off the shelf stock. When I got them home, I opened up a package and noticed something odd.

They're .223 full metal jacket rounds. On almost half of the rounds there were inconsistencies and irregularities around the area where the bullet is placed in the casing.

So if you look at a bullet before it's put into a case, it has that little ribbed area that goes just inside the casing. Parts of the copper jacketing on some of the bullets flaked back and were sticking outside of the case inversely, while the rest of the jacketing was snug inside the case. The bullets are solidly in the case, but about a third to a half of all the rounds had these irregularities.

I took a small flathead screwdriver and went through the rounds an scraped off the little flakes of the jacketing off, and they came off easily enough. But, some of them still have the tiniest bits of jacketing still kinda wedged back out of the casing. Just the tiniest bit.

Could these rounds damage a M&P 15 sport's barrel bore? I suppose at the very least it may cause very poor marksmanship.

I haven't shot any of this stuff through the gun, and I haven't contacted the seller again. I didn't take pictures, either, sorry. I hope I described it well enough that perhaps someone has seen these kinds of irregularities and will know what I mean.
 
The ribbed area you speak of sounds like you're describing the cannelure, as for the flecks of jacket material; other than some slight accuracy issues it won't damage your bore. Remember your barrel is hardened ordnance steel; the bullet jacket is soft copper.
 
The reference of "copper washed steel jackets" I believe is to the casing, not the bullet.
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Actually, probably not. There have been a lot of steel jacketed, gilding metal plated bullets produced. The cost savings per bullet isn't that much but when you're cranking out a billion rounds a year that $0.001 per piece savings adds up.

BSW
 
Much if not most Russian ammo is made with a mild steel jacket with a thin copper plated finish to prevent rusting, and to help lubricate the round during the feed cycle.

If you file or even scrape the copper "jacket" you'll find it's a very thin plating of copper over steel.

"Copper washed steel jackets" very much does not refer to the cases, since most Russian cases are either coated with lacquer, or these days, a polymer coating.
In any case, no one refers to a case coating of any kind as a "jacket", steel or otherwise.
 
Do the bullets (projectiles) stick to a magnet?

If so it's probably a copper washed steel jacket, as mentioned above.

Shooting steel through steel can lead to some wear & tear if you don't have a chrome-lined barrel. Chrome lined bores are much harder and wear resistant than normal barrel steel.
 
The cost savings per bullet isn't that much but when you're cranking out a billion rounds a year that $0.001 per piece savings adds up.
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...and even more in countries that don't have much in the way of copper resources.
 
Shooting steel through steel can lead to some wear & tear if you don't have a chrome-lined barrel. Chrome lined bores are much harder and wear resistant than normal barrel steel.
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Is that why mosin nagants don't have chrome lined barrels?
 
Is that why mosin nagants don't have chrome lined barrels?
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mosin nagants are bolt guns with small magazines and large bores. their max rate of fire would not be considered even a moderately harsh schedule. and the expectation of accuracy when they were made was similarly not particularly aggressive.
 
I don't recall where i saw it but a test was conducted of barrel life when copper washed steel bullets were used vs traditional copper jacketed lead bullets. With the latter the barrel lasted nearly twice as long.
 
Yeah, it's a fact that normal steel barrels wear more quickly when shooting steel projectiles.

Chrome has a very high rockwell hardness, and can stand up to it better. But it's certainly not immune.

The higher the rate of fire, the hotter the metal in the throat gets, the easier it is for the steel bullet to wear the lands down. So rate of fire plays in. Rapid fire 30 of them out of a semi-auto with a non-chrome lined barrel and I guarantee you're doing at least SOME damage to the throat. Throat erosion is what will kill the barrel's accuracy potential in the end.

I wouldn't be worried, whatsoever, if I was going to shoot a few dozen, or even a hundred or two, slow fire. A chrome lined barrel should be good for 10-20k, or more.

I would NOT shoot any - whatsoever - out of my match grade barrels, regardless of the rate of fire.
 
Whether the flecks of material are gilding metal or steel, I can't imagine that ironing them into your bore under 55,000 PSI at 3200 fps is going to do anything good for your barrel. Here's the question that I'd really like to have answered, assuming that some of the loose material IS ferrous, what the heck would you use to remove steel fouling from a steel bore? Table salt and water?

Here's a link to a torture test comparing the wear imparted by gilding metal vs copper washed steel jackets under HEAVY use.

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/
 
The hardchrome was almost certainly as protection from corrosive primer residue as well as increased resistance to wear from full auto fire.

Rifles shoot out their throats. The only way to stop that damage is not to shoot the rifle. OTOH, compared to the white hot plasma and erosive effects of burning powder, there isn't much the rifleman is going to do that would increase that wear rate.

BSW
 
Swampman said:
Whether the flecks of material are gilding metal or steel, I can't imagine that ironing them into your bore under 55,000 PSI at 3200 fps is going to do anything good for your barrel. Here's the question that I'd really like to have answered, assuming that some of the loose material IS ferrous, what the heck would you use to remove steel fouling from a steel bore? Table salt and water?

Here's a link to a torture test comparing the wear imparted by gilding metal vs copper washed steel jackets under HEAVY use.

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/
Click to expand...
Wow, that's an awesome study. I guess I will be abandoning my plans for pounding tons of cheap ammo through my rifle.
 
Originally posted by FireInCairo, "Wow, that's an awesome study. I guess I will be abandoning my plans for pounding tons of cheap ammo through my rifle."
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And just WHERE were you planning on finding these tons of cheap ammo in this day and age? :scrutiny:

Seriously, the only way to shoot well, is to shoot, a lot. A goodly portion of that can be accomplished with a good .22, but it's going to take shooting your AR to get really good at shooting your AR.

Face it, barrels are just as much an expendable item as springs or ammunition.
At current ammo prices you'd spend enough on ammo, even "cheap" Russian ammo, to buy at least five barrels before you wore the first one out.

This doesn't mean that I think anyone should deliberately abuse their weapon as was done in the test that I linked. If abuse of firearms was illegal, anyone that participated in that test would be convicted of first degree mechanical sadism.
Bear in mind that the whole point of the test was to abuse the weapons to the point of failure and (possibly) convince people to buy higher markup US made ammunition, they ARE an ammo retailer after all.

If "copper washed" steel or "bimetal" jackets were really as destructive to barrels as that test showed, I seriously doubt the US Army and Marine Corps, as well as the German Army, would use them in their 7.62x51 machine guns.
 
Swampman said:
If "copper washed" steel or "bimetal" jackets were really as destructive to barrels as that test showed, I seriously doubt the US Army and Marine Corps, as well as the German Army, would use them in their 7.62x51 machine guns.
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Back in the late 90's I bought a Federal Arms 91 rifle, it was a rebuild of a parts kit of a G3, back when barrels could still be obtained.

Problem is, the barrel they used was from the original kit, and completely shot out. It's probably the least-accurate rifle I've ever purchased.

I don't know how many thousands of rounds it had shot out of it, or what the ammo the Germans used before cutting it up to ship over here, but it was done for before it ever got put in a new receiver. Problem is, on a G3, replacing the barrel is no small task.

Same story with a Yugo SKS I bought. BEAUTIFUL rifle. But the bore was done for before it ever hit our shores. Not pitted, not corroded.. just.. shot out. Those aren't exactly easy to swap out, either.

Both rifles hold minute-of-barn-door accuracy.

Before blasting away with cheap bimetal ammo.. it's worthwhile to consider how difficult it is to swap out a barrel. The barrels in that test shooting bimetal were (according to the testers) "completely shot out by 6,000 rounds." Granted, that was one mag dump after another, but that's also a heck of a lot lower life-span.

Considering that once the barrel is done-for on a great many rifles, the rifle itself is pretty much done for, that's a pretty serious concern. Sure, swapping out a barrel on an AR-15 is quick and easy. But not all rifles are AR-15's. :)
 
I've been shooting Swiss-made Geco bi-metal 9mm through my P-210. After buying the gun I bought a mag on line and the seller recommended it. He turned out to be an experienced P-210 shooter both stateside and in Switzerland.

Fwiw, someone actually posted a lab analysis of the RUAG Geco 124gr. FMJ:


_____________________
Results

Jacket wt.-18.32grains
Core wt.-105.422grains

Jacket
4.83% Cu (plating)
94.6% Fe
.63% traces of Zn, Pb, Bi, Ni, Cr, Al

Core
98.65% Pb
1.3% Cu
<.05% Al, Fe, Bi, Zn

Samples run on ICP-OES in aqueous acid solution (digestion), 10% Aqua Regia by volume.

Yes, 95% Iron jacket (not steel) with a 5% copper plating. Core is lead.
__________________
 
Rifles wear out fastest that have small bores and high velocities. That's why 5.56 NATO is so rough on barrels and why they have such a short life. AK barrels (larger bore and lower velocities) last much longer.

I don't expect to ever shoot out my semi-auto Uzi barrel. The huge bore (compared to .223) and low velocities should make for a barrel that'll last my lifetime. Barring squibs or a overcharged ammo explosion.

BSW
 
BSW - yeah, that makes a good deal of sense. Velocity plays in to it for sure. My last 300 Win Mag barrel lasted about 1700 shots before it started going south. Throat was gone, gone, gone.. still accurate as all heck but it got to a point where I just couldn't load bullets long enough to keep up with it. And if I didn't load them long, I had horrible velocity consistency and exceptionally bad fouling. (I think gas was getting AROUND the bullet as it started moving, if I didn't seat it out to the lands).

Eventually I reached the end of the bearing surface on the bullets, couldn't seat them longer, and the fouling got to the point I was having to clean the rifle every shot or two. I was SO reluctant to rebarrel it, as it was still shooting sub .5MOA groups. :(

But all good things must come to an end.
 
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