When using an unscoped weapon (bow, shotgun, handgun) before you start the hunt, get a spotting scope.

When you are hunting use your spotting scope to look at the animal.

When the animal is close enough to get a good shot place the cross hairs of the spotting scope on the animal if it is stopped, lead it a little if it is moving.

When you get the cross hairs in the right position, hit R3 to bring up your weapon of choice, aim in and fire.

It is a sure hit everytime.

Good luck