steel cased ammo in an ar is it ok to shoot?

[billy ahring]

Picked up a couple of boxes of steel cased 55 gr .223 ammo for my ar. It is Tul ammo brand from Russia I believe. Is it ok to run this through my gun or should I stick with brass cased rounds? Is it ok to shoot as long as I follow a prescribed regimen? Just wondering don't want to do any damage and find out the hard way later.