Need Help CCI 22 ammo

[S&W2244]

I have 100 round plastic boxes of CCI Mini Mag High Velocity 40 Grain Plated Round Nose 22 cartridges. In one box the brass cases have brown stains or tarnish on them. Some are the size of pin heads others are larger. Never saw this before. What might be causing this? Are these rounds safe to shoot? Thanks for your help.

 

[alwslate]

Seems to be a very common occurrence with many different types of
factory ammo and unfired brass. I wouldn't worry about it.