steel cased bullets shouldnt just sit in a hot un-chromed chamber. the coating will migrate from the case to the steel chamber walls and can in extreme cases cause fail to extract. thats why some ar15 can run steel case and some have problems.
if yours isnt chromed in the chamber just dont let it get hot and you will be fine.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent