Confused about Federal Champion Ammo.

Hello everyone.

I recently bought some Federal Champion Ammo. It's 40 S&W 180gr FMJ FN. I didn't realize until I bought it and got home that on the box it says "Do not use in firearms with ported barrels or ported recoil compensators". I have a G23C.

My confusion is that I bought the same ammo from wal-mart that does not have this warning. As far as I can tell, there is absolutely no difference between the ammo. The two boxes are exactly the same except for the warning.

Has anyone else ran into this problem before? Should I just sell the ammo with the warning label since I can't return them or should I try shooting them anyway?