Winchester 7.62 147gr FMC JB bullets

[jrpilot]

I just got some of these bullets. They are not pulls. New in a case. A magnet does stick to them as some said Winchesters wouldn't.

My main question and concern is if they will be harder on a barrel and cause extra wear. I got these for SHTF loads but I would like to shoot some as well with the kids for cheap plinking rounds. I have a nice barrel, and dont want to chance anything with it.

Im an experienced reloader, but i just have never messed with cheap bulk bullets.

Thanks for the info and help.

 

[Ravenworks]

Just shoot them, it would probably take many thousands of rounds or better before I'd worry about a replacement barrel

 

[hlee]

Lucky gunner did some testing a while back. You may find this interesting...

Brass vs. Steel Cased Ammo - An Epic Torture Test

This comprehensive 40,000 round brass vs. steel cased ammo torture test examines at key indicators of ammo performance and cost in AR-15 rifles.

www.luckygunner.com

Bimetal Jacket Impact
As indicated by accuracy testing, the steel cased/bimetal jacketed ammunition caused accelerated wear to the inside of their respective bores.

The barrel of the Federal carbine had plenty of life left after 10,000 rounds at extremely high rates of fire. We subjected the Wolf and Brown Bear barrels to the same rates of fire and they were completely “shot out” by 6,000 rounds.

At the end of the test, the chrome lining of the Wolf and Brown Bear barrels was almost gone from the throat forward. The barrels had effectively become smoothbores, with the rifling near the muzzles acting only as a mild suggestion on the projectiles. A throat erosion gauge could be dropped into the bore from the muzzle end with absolutely no resistance.

 

[jrpilot]

Not sure if these are bimetal jackets. I was reading that there is steel around core with a copper jacket on. The m80 bullets.

 

[smoothy8500]

The Winchester mfr 7.62 FMJ's are bi-metal with lead, not steel core. The copper layer is pretty thick compared to the Wolf or Brown Bear bi-metal projectiles that were used in the posted 5.56 test article. However, Winchester was one of the least accurate FMJ's that I have used.

 

[Ledzep]

Even if the copper is thicker than the rifling is tall, it will cause increased wear. The lands don't technically "engrave" into the bullet like a cutter. It's more of a swage. If you ever find a big enough piece of jacket after a bullet's been fired you can see the indentation from rifling on the inside of the jacket. At any rate, the entire jacket is being pressed and the steel, as soft of an alloy as it is, is stronger than pretty much any copper alloy and will require more force to swage the rifling into it. More pressure, more heat, more friction on the lands, less life. Worth worrying about for a few hundred rounds over the barrel's life? Probably not. As a steady diet, yes.

 

[jrpilot]

Thank you for the info.