Shot Size, Load, and Length
Shot comes in various sizes. The sizes are numbered, but the larger the number, the smaller the size of the shot. So for example, No. 9 shot is very small while No. 000 shot is large. Choose the right shot size for the animals you are hunting. As a general rule, the smaller the game, the smaller the shot pellets need to be. Some big game species may be hunted using shot or slugs. Check Montana’s hunting regulations before you choose your ammunition!
You can buy the same gauge shotshells with various powder charges. The boxes may be marked target, field, or magnum load. Magnum loads have more powder and more shot than target or field loads. A 12-gauge 2¾-inch magnum shell, for example, will contain ¼ to ½ ounce more shot than a standard shell of the same size and gauge. Magnum shells are often longer than standard shells.
The length of a shotshell is normally given in inches and is based on the length of the spent hull. Common lengths for 12-gauge shells are 2¾, 3, and 3½ inches.
Warning: The new 3-inch and 3½-inch shells will not work in a shotgun made for 2¾-inch shells.