The only way I'd give a shit about what kind of ammo I'd be putting through a rental is if I had to clean it at the end of the day. Personally, I don't see any responsible business owner letting people come in and take apart a rental gun, as you'd have no idea whether or not the person knows how to put it back together correctly. The range I shoot at does rentals and there's only a few people, myself included, that they'll let take down the rentals and clean them. The way I see it, if you're not cleaning it, who gives a fuck what cheap ass brand you're throwing through it as long as it's safe to shoot.