Will "bi-metal" ammo increase barrel wear...?

[Snowman366]

I notice that some imported ammo is advertized as having a "bi-metal" jacket. I understand that this means it has a steel jacket with a thin layer of copper/zinc plated over it somehow...correct?

Will shooting a lot of this sort of ammo increase barrel wear in a non-chromed rifle bore? I'm talking about 7.62X54r and 7.62X39 caliber just to narrow it down a little.

Thanks...

[blackpowderbill]

The "steel" used in bullet jackets is as soft as steel can be. I have been told that it is more akin to wrought iron than hard steel. In any event it should not cause any harm to your barrel. High grade Euopean hunting ammo loaded with soft point bullets will often have "steel" jacketed bullets. Norma and RWS come to mind.

[1911crazy]

I found out all the jacketed bullets are a thin layer of steel with a coat of copper on it. I found this out during my testing in wet sand with my reloads.  All of my bullets had a steel copper coated jacket.  Some military surplus bullets have a white copper coating too like the turk 8mm ammo.

Knowing this I don't shoot too many practice rounds out my very accurate high power guns. (magnums)  But i don't think we'll hurt the military barrels there made for this ammo.

OT; I'm not sure which would hurt the gun more using the 7,62x39 steel cased ammo.  The steel jacketed bullet or the steel case.

Another good question is has anyone personally ever worn out a mosin barrel?

Or has anyone worn out a chamber in there sks or ak47?

[cbxboy]

As 1911 points out I would not fear this in anyway.  Do you realize just how many times you need to get hit in the shoulder before the rifle would "wear out"? 

Lets do some math......an SKS or Mosin at $200

Ammo - Military surplus  .20 a round times 8000 = $1600
New production ammo    .64 a round times 8000 = $5120

I am ASSUMING you can wear out a barrel in 8000 rounds -- I don't believ this but lets call it 8000, adjust accordingly.

I don't care WHAT rifle you buy if every time you squeeze the trigger you put .44 in a jar you can buy a NEW rifle with the difference.

With this math adjust anyway you wish.....my opinion is that in just 500 rounds you will save enough to buy another rifle.  The math just does not add up in my opinion to be picky on ammo, shoot milsurp and shoot it often!

Reload if you wish--cheaper and fun.

[Double 30]

In a hard chromed bore I would worry less than in a non-chromed bore. I've recovered bimetal bullets and every one showed that the rifling penetrated to the steel. The reason some countries used bimetals is that steel is less expensive than copper ( same reason for steel cases) and they will generally deform less when penetrating than a straight copper/nickel jacket. Bimetals are my bullet of last resort. Having said that , if you have a rifle with a roughish bore , they can knock off some of the roughness. Couple hundred rounds can be a poor man's firelap... 

[1911crazy]

I wonder what the barrel life is between the 7,62x39 in a chrome lined bore vs a non chrome bore?  I would think its much more than 10,000rds. I think its more like 100,000rds. out of there chrome lined bores on the ak47's.


OT; Think about it if the manufacturer uses a chrome lining in his bore he can use the barrel made from a lesser quality steel because the hardness is in the chrome lining. You don't really need a chrome moly barrel with a chrome lined bore its just silly.

I think the most barrel wear happens in the modern magnum rifles with speed and power being the factors.

[Snowman366]

Thanks so much, guys.

[1911crazy]

I really don't think by shooting alot of FMJ bullets your going to wearout the barrel any sooner in a non chrome lined bore.

BTW;  I did try to install a chinese norinco chrome lined barrel into a yugo sks recently too.  I found the thread timing to be off 180 degrees.  This put the gas port on the bottom of the barrel.  While it would fit the gas port and pin slots were 180 degrees off.

[SHOOTALL]

wasn't chrome used to help the bore not rust in wet climates ? I have an 870 that came lined for rust protection , made for duck hunting .

[Totenkopf]

wasn't chrome used to help the bore not rust in wet climates ? I have an 870 that came lined for rust protection , made for duck hunting .

Yes, it's also harder and slicker though. So less wear and less cleaning. On the negative side less accurate though (in rifled bore).

Most of us can't afford to wear a barrel out. You will be safe with the copper washed bullets, just make sure they are non corrosive like wolf or silver bear. The steel cases they use are harder on extactors though. If you plan to shoot 1000+ rounds, you may want to find a source for a new one if this is a nagant. On the 7.62x39 if sks or ak no worries on the extractor because they are stronger metal. My old k98 has had many rounds through it, all were washed bullets. It's still a tack driver by k98 standards. Same can be said for ak, though not a tack driver, hasn't gotten worse.

[1911crazy]

If you want an accurate "AK" style semi auto i'd look for a russian izhmash saiga.  They come in 223 rem and in 308 too besides 7,62x39.  The russians focued on making them more accurate than there ak brothers and they did it with success.  My 308 saiga w/16" barrel using south african 308 ball ammo will shoot 1 1/2" groups @ 100yds. benchrested if i do my part. For some reason the russians @ izhmash did admit the two american calibers of 223 and 308 are more accurate than the russian calibers are and they think its the design of our brass case. Don't forget your buying a brand new russian izhmash ak47 in a sporter wrapper, its not someones butchered rework its the real thing and its brand new.  Its been battle proven worthy in any climate and soil too.  Rumor has it there is a delivery of saiga's comming here soon so my dealer says.