There's a little thing called the Geneva Convention under which various weapons of mass or personal destruction are banned.

Amongst these are hollow-point bullets. Apparently they are unfair, somehow. The AR-15 rifle does the same trick with an unstable .22 bullet that tumbles when it hits something, but it's technically "legal"

A century or two ago, the Pope was in charge. At that time a popular machine gun could fire "square" bullets to grip the rifling real well and get good accuracy and range. The Pope declared that it was proper to use those bullets agains "infidels" but not against "christians".

Tie your arm behind your back...