Mark,
IF you were picking up a "bunch" of ammo, say on one of the pre-season sales, you'd want to check inside the end flap of the boxes to make sure that it ALL comes from the SAME lot.
That way you could sight in your rifle and know that you could go to any round in any of the boxes you bought and have reasonable confidence it would shoot the same.
That's because it's all loaded with the same lot of brass, powder and bullets (hopefully).
So, when they punch out a bunch of brass, it's done in lots too.
Mix up a bunch of lots of brass and you "might" get different results from case to case. This might happen, or it might not.
Precision match shooters would make sure everything is the same.
For your purposes it might not be critical...
If it's clean it'll reload just fine.