Light Rust on loose rounds

I was recently given some loose Tula 5.45 from a friend that sold his 74s and no longer has a need for the caliber. Looks like the majority of the ammo he gave me was stored loose in an ammo can and has developed some light rust. Some rounds are worse than others. I went after some of them with a brass brush and the tarnishing/rust didn’t really want to budge. Are these safe to shoot as is or should I discard?

I was recently given some loose Tula 5.45 from a friend that sold his 74s and no longer has a need for the caliber. Looks like the majority of the ammo he gave me was stored loose in an ammo can and has developed some light rust. Some rounds are worse than others. I went after some of them with a brass brush and the tarnishing/rust didn’t really want to budge. Are these safe to shoot as is or should I discard?