It will shoot fine, dont worry about it.

I left 3 rounds outside in the rain,cold, hot, etc for 3 months to test to see if they would fire.The cases were rusted over 90% and the bullets were a weird color.

All three rounds fired and ejected without issue, and they were really rough looking.

Keep that ammo in a steel ammo can with a good seal and you wont have to worry about it.

Actually I was just getting ready to post about this. I bought 1000 rounds of tulammo early this summer, I shot alot of it and stored it in my basement that is very humid. The remaining ammo has a few rust spots and has hang fires. Most are so slight u can hardly tell every once in a while one will hang for half a second then go off and one didn't go off at all. I have some Barnaul ammo that I've had for 20 years, goes off every time with no delay, it has been stored in the same place. The ammo I stored up stairs works fine.

It will probably shoot better with rust. Heck it is an ak

I was actually shooting mine through an AR and vz58, lol. Wonder why they don't seal the cases anymore, that would solve the problem and make the ammo much more reliable.

Shot some yesterday.   Fireded and cycled fine.  Accuracy sucked compared to me ar but optics and shooter could be a lot of that.   Could still hit steel plate at 100yrs 2/3 time.