Typical deer hunting rifle ammunition comes in two types: heavy, large-caliber, slow-moving bullets, for short ranges and light, small-caliber, high-velocity bullets for long distance shooting. Both are effective in hunting deer but one may fit your hunting situation better depending on where you live and what you are hunting.
A typical example of the first deer hunting rifle ammunition is the classic .30-06 Springfield. With the .30-06 you have good flexibility in the size of the bullet. With the larger 150 grain and 180 grain bullets, you can use them to hunt larger game such as mule deer and elk. .30-06 caliber rounds are also ideal for ranges under 150 yards.
7MM ammunition is an example of the second type of deer hunting rifle ammunition. The bullet has a higher velocity on leaving the gun, has less drop than the .30-06 caliber rounds, and has excellent knockdown power. This makes the 7MM more ideal for long distance use above 150 yards.
Both types of ammunition are available for many types of commonly found deer hunting rifles.