Steel vs. copper ammo . . .?

Absolutely, steel will wear the barrel faster than copper.

Yes, but.....

Keep in mind that except for the copper wash on 22 rimfire bullets, very few have copper jackets. The typical bullet is clad in gilding metal, a form of brass that's generally 90-95% copper, with zinc added to harden it. Cupro-nickel jackets do the same. The steel in steel-jacketed bullets is a mild steel, alloyed in a way as to make it less hard. So there's a difference, but less than you might think.

Second, it's an AK, likely with a chrome-lined barrel (very hard stuff), and you'd be hard pressed to tell the difference in accuracy between a new barrel and one that's shot out after ten thousand rounds have been put through it.

So you may have a point, but it isn't far from arguing about how many angels can dance on the head of a pin.

I have read about this ,and it depends on the softness of the steel that is used in the bullets. Copper ammunition will probably be much easier than steel jacketed on the barrel. Try to avoid the steel jacketed ammunition ,and tell your step son to thoroughly clean the gun because a lot of surplus ammo is very corrosive. Even if he fires one round of surplus out of the gun tell him to clean it like his life depended on it. I do not like corrosive ammo. Tell your son to get non corrosive ammunition so his gun will not rust out. Russian guns are notorious for working in rough conditions so I am sure your stepson will have a good experience with either type of ammunition as long as he really cleans every nook and cranny of the gun.

I saw the same article as Billygoat. I have fired thousands and thousands of bi-metal steel-cased ammo through several different guns, and never seen any real signs of accelerated wear. One thing to check though: Just because it's steel cased doesn't mean it's a bi-metal bullet. Another thing to consider is that certain alloys of copper are just about as hard as certain alloys of steel which means the steel under the copper coating on a bi-metal bullet is likely going to be much softer than the high quality, chrome plated steel of your rifle barrel.

Steel Jacketed Bullets

it depends on the guy's AK. most AK's feature a chrome-lined bore, which is 2X harder than steel and won't be affected by steel jacketed ammo as much as a plain steel bore will be.

I haven't seen any AK's without a chrome steel bore, but they probably exist...

Based on my experience with a Mosin and a wasr-10, one with a plain steel bore and the other with a chrome steel bore both shooting steel jacketed ammo, the mosin with it's plain steel bore went from brand new ot pretty worn out in about 2000 rounds, the AK with it's brand new chrome bore to now, it's been about 6,000 rounds and it's still brand new.

with a plain steel bore the differences in wear between copper jacketed and steel jacketed ammo is apparent after about 2-5k rounds.

with a chrome lined steel bore there probably won't be any visible or noticeable differences until you get past 15k rounds for copper or 10k for steel rounds...

I'm assuming you are talking about bi-metal jacketed bullets or copper-washed jackets versus actual copper jacketed ammunition. Lucky Gunner conducted a 40,000 round torture test using a number of different ammunition types. They found that bi-metal jacketed ammunition DOES wear out the rifling faster than copper jacketed ammunition, but the rate of accelerated wear isn't really fast enough to make much of a difference to most shooters. In other words, if 2,000 rounds is more than your stepson is ever going to shoot through that AK, then it doesn't really make a difference.

If you're talking about steel-cased ammunition versus brass-cased ammunition, then that's NOT going to be a problem for a Kalashnikov.

I can't recall any studies I've read but basically I'm of the same mind as you i.e. steel jacketed will wear on the barrel faster than copper. I could be totally wrong but I don't think I am.

People say Steelcase ammunition erodes the throat faster. But they have nothing to back up that claim. That Russian stuff uses a softer type of steel so no, it would not wear out the barrel faster.

I also think it would wear out the barrel faster but that depends on the type of steel also.