Lots of ammo taxing schemes running around. As of right now, a lot of them are tied to ammo serialization laws.
Kentucky actually had a serialization law proposed (that died a quick death) that would include a tax of $.05 per round. Not a big deal if you buy a box of 20 rifle rounds. Pretty big deal if you buy a brick of .22lrs.
And, if I'm not mistaken, isn't there an additional tax on outdoor "sporting goods" like ammo, bows, arrows, guns and the like?
"He who laughs last, laughs dead." Homer Simpson