Why did you even think that?
No, they should either re-define what a "handgun" is, or simply repeal the section of the underlying law which allows unelected ATF staffers with political agendas to conjure up regulations on what ammunition is banned.
If they are going to ban ammunition, then the Congress should just list the banned ammo and vote on it. I think we'll see a very short list if members of the House have to explain their votes to their constituents.
What?