i was wondering why alot of people go for a heavier bullet when hunting whitetail? i see alot of people using 180gr's in the 30-06sprg's. i always thought a lighter bullet like a 165 or 150gr. would be better to hydorstatic shock being better with a smaller sized bullet.
from what i have learned on these kind of topics is that. the lighter the bullet the more hydrostaic shock and the heavier the bullet. the better the penetration and stays together better.since they do have better bullets nowadays i lighter grain size in a partiton would be the best of both worlds. but with a whitetailed deer being not that hard to kill with lighter bullets why do alot of people use heavier bullets on them?

Quilly, a lot of people have a favorite load that shoots well in their rifles and they stick with it whatever the game is a simple explanation. 180 in an 06 will handle everything from Deer to Moose. It also simplifies life but is bad for the ammunition manufacturers.

Quilly, also consider this:

The lighter the bullet, the thinner the jacket as found in 110gr 30-06 varmint loads for fast expansion. Heavier bullets have the thickest jackets like the 220gr+, used for the bigger North American animals where deep penetration is desired. When used on small creatures like the whitetail, they may not expand and behave more like a FMJ. I stay in the 150gr weight class myself because these .30 cal bullets were designed by the bullet makers for best expansion on deer sized animals, and who am I to argue with a ballistics technician. My years of field use with handloaded 150gr Speer's proves it is so right for the job. Hunting the bigger northern deer, 165gr would work well enough.