[wild cat mccane]

If you look into it there's interesting stories about who actually makes this Federal cases (Fiocchi). Don't know if it's still true.

I had no idea, but started looking. Most complicated case history of any cartridge I can think of.

The "FNB" kinda points to Federal, made by Fiocchi and not FN or Federal.

But Federal is so big, it might not be true any longer that don't make it, but you bag clearly is FNB marked, so that might not matter at all.