I just got a 22 Hornet, would a head shot on a 100 # hog drop him?
Like a rock. Even a .22 LR behind the ear will drop them. Just don't look for it do do any real damage on a body shot.
I changed to a .22 Hornet over 12ga for a turkey gun this past year. Down here, you never know what will show up when you are calling turkey. Could be a fat hog or it could be a coyote.