I have shot steel cased ammo through my ARs without any problems. It wasn't much but it worked just fine.

I think the most common problem with Tulammo is it's very dirty burning powder and you'll have more feed and ejections problems the longer you shoot it because the chamber tolerances are much less compared to an AK. You can run Tulammo all day through an AK with no problems.

Also I think the steel bullet jackets on Tulammo wear out the barrels a little faster than copper jackets but you need to be shooting several thousand rounds of steel jacket to notice.