Hole in the heart will do it. Sounds like the round didn't do a heck of a lot of damage. It is surprising how little internal disruption can occur. I prefer soft pellets and soft bullets for small game hunting. From my experience, a .22 soft pellet will drop a squirrel as fast as a standard velocity .22 bullet, if placed properly, and perhaps better than a high velocity round nose will. Hollow points have their place, but for squirrel and rabbit, they destroy to much meat.
Veggies are cheaper than meat, let mr bunny have a bit of em before he goes in the dinner pot.
