The .452 240 gr XTP Mag is plenty big enough for deer.
Agree with Triple while I like the 300 gr. XTP and have killed 3 deer with the reg. .45 cal.... Ive killed at least 40 deer with the 240 gr. xtp from 5 yds to 165 yds with 85-100 gr. pyrodex rs and all were pass throughs and dead with in 85 yds most within 35 yds..