Hi Shaun, I have several thousand rounds of 10mm Hard Cast from DoubleTap, Underwood and my own hand loads. It is really meant for penetration on Large, Dangerous game that has thick bone, muscle and mass. You can hunt with it, but shot placement must be in the vitals as it will not expand or deform. Deer are thin skinned and light muscled game. manufacturers like Winchester and Federal actually put game recommendations on their ammo boxes. The XTP's will give you the best combination of penetration and expansion on deer. the Hard Cast will zip through a deer.