It's become customary, in CQB, to use a suppressed .22 HP, for head shots.
Range is seldom an issue.
No noise, so bystanders aren't spooked and start becoming more difficult targets.
A .22 HP has enough inertia to punch a hole in and then rattle around inside the skull vault, without as much chance of continuing out the back.
It's a quick drop, since living brain tissue is about the consistency of Camembert cheese and the bullet is about a .5 inch wide after penetration...
Just saying.
Yup.