I honestly did not know that. I think you just gave me something to research. Thanks!I personally would not shoot Tulammo steel through that nice of a barrel. Tulammo uses a bi-metal jacket (thin layer of copper over steel). If you had a sub $150 melonite treated barrel I'd say shoot it all day long. The cost savings would outweigh the cost of the barrel. If you want to shoot steel cased ammo, buy Wolf WPA which has a true copper FMJ bullet.
I read something once where they said shooting domestic ammo was better for the barrel. I don't remember the exact info but if I remember right, it was something like 10,000 rounds of the wolf or Tula stuff would have your barrel shot out. Let's see, the steel case stuff is something like $.35, while the stuff they are comparing it to was close to $1 a shot. After 10,000 rounds, that's $650 difference. I think I could buy a few AR barrels for that. That is if I could even afford to go burning thru 10,000 in the first place.
There is a LOT of that cheap stuff being used, because you get the most "bang for your buck", and that is eating into the market share pretty hard. I see these "studies" that demonise the steel cased ammo and marketing ploys. And little more.
Wolf WPA is a bi-metal bullet.
Wolf gold is brass case copper bullet.
Wolf copper jacketed is steel case copper bullet.