We�re talking small deer now - under 150 lbs - so keep this experience relevant;
As a close comparison, I�ve killed a few deer with a 170 gr JHP loaded to 1550 fps in a .41 Magnum that kills �em pretty good, but I�ve stayed away from bad angles and big bones when using these lighter bullets. Several have been instant kills with not so much as a kick after they hit the ground. Unless a hit disrupts the CNS, I never get that kind of reaction from a 210 gr JHP at 1300 fps.
That being said, heavier bullets certainly provide more reliable penetration from my experience, but they will not necessarily yield a better reaction from the deer, i.e. a short run with a minimal blood trail.
