Federal brass flash hole question

I bought some once-fired brass which had a couple hundred Federal cases mixed in.   They were all shot by the individual I bought them from.

I was cleaning and drying brass this week and noticed they have 3 different flash hole sizes.  I can easily sort them into the sizes by sight and confirm the difference with the shaft of a small drill.   The smallest size is the same as all my other brass.

1) are the larger two flash holes related to the lead-free primer trend?  They are still Large Primer.
2) will I see any significant POI difference from the larger flash hole?  That will tell me whether to trash those cases or to use them for practice.

I will try to load a picture tonight.

Aprilian: Do any of those Federal cases have the convex bottom surface of the cases?

Not that I noticed Gary,   I have seen SPEER cases with convex bottoms.   If the Federal did, what might that indicate?

Somebody else on this forum, or another forum stated that Federal, Speer, CCI, & 1 or 2 other ammo mfgs. are owned by a parent company. Outdoor, Inc. to ber exact. All of those brands have or are of a lower cost ammo and share the same machines. Consequent, those brands will have the convex bottom.  I've actually seen some Federal that has their name are large primer & contain the convex botto. I've never really played with any of those cases but I do rash them just to avoid confusion with better cases.

here are representatives of the 3 sizes

I suspect two things. 1. I wonder how much difference there was new and 2. Once fired??