All of my hunting with pellet guns have been on birds, house sparrows, starlings, and crows. The big problem is speed, as these birds are cautious creatures when close, so I usually aim at their body. most of the time the gun is fired offhand, sometimes I can use a partial rest.
Most of the crows have been hit at a distance on the ground, hence, they are not aware of my intent to shoot them. I shoot out of a third floor window which allows me to aim straight to the target on the ground at 50 yards, and a few inches high at 100 yards. As heights negate the need to allow for the rainbow trajectory effect which would normally be encountered on a level plane at ranges of around 100 yards, from rifle to target, the window position helps alot. The last two crows I hit were measured at 56 yards, they were still alive and I had to go out and deal with them up close with whatever club I had despite solid hits in the main body. I was using powerful .177 and .22 RWS rifles, one with a scope, and the other open sites. I might try hitting them again, or a 3rd time to see if that helps. My concern about head shots at longer ranges is that it might only nick part of them, and not cause fast death, so the body is chosen as the site to hit.
The hollow points have been very disapointing at 100 yards. I can see them wander to the left and right routinely, not coming close to the target most of the time. The pointed tips and the flat heads work really well at distance shots. My longest shot was about 175 yards with a flat head (RWS Hobby) in .177, missed the target but was close with 2 of the shots fired. This shot required sizeable trajectory allowance to get near them, and the rifle was a Chinese side pump, not the most powerful on the market, but it had some merit, though limited.