SHOTSHELLS

Shot Sizes

Shotgun Ammunition

Gauge

Term used to designate bore diameter of a shotgun; gauge is the number of lead balls with diameters equal to the diameter of the bore that, when combined, weight one pound

Shot Sizes

Shot size is adaptable to the game being hunted. As pellet diameter decreases, more shot can be placed in a standard shotshell load. The smaller the shot number, the larger the shot size.

Non-Toxic Shot

Non-toxic shot is required throughout the U.S. for waterfowl hunting. Studies showed that many waterfowl died each year because of lead poisoning. Lead pellets from traditional shotshells were picked up and digested by waterfowl. The toxic effect spread to other birds, such as the bald eagle, who consumed the poisoned waterfowl. To reduce this problem, conservationists worked with shotshell manufacturers to produce effective alternatives to lead shot—steel, tungsten, or bismuth shot.

How Ammunition Is Fired

The firing sequence for handguns and shotguns is very similar to this sequence shown for a bolt-action rifle.

1. The bolt moves forward, compressing the firing pin spring and inserting a cartridge into the chamber.
2. The firing pin is held back under spring tension.
3. When the trigger is pulled, the firing pin moves forward, crushing and igniting the primer in the cartridge base.
4. The primer ignites the gunpowder, generating gas pressure, which forces the bullet forward and out of the barrel.

• Shotgun shells (shotshells) use a slug or shot as the projectile(s).
  A slug is a lead projectile used for hunting big game with a shotgun.
  Shot are multiple pellets fired through a shotgun barrel. Shot size is adaptable to the game being hunted. This type of projectile is typically used to hunt game birds and small game animals.
• The shotshells must match the gauge and shell length specified by the manufacturer exactly. This information is usually found on the barrel of the shotgun. Shotguns may be chambered for 2 ¾-inch, 3 inch, or 3 ½-inch shells. This refers to the length of the shell after it has been fired. Read more about correctly matching ammunition to your firearm on page 19.
• You also must choose the correct type and size of shot for the shotshell. In general, as the size of your target decreases, you should decrease the diameter of the shot you use.
  Diameter: As pellet diameter decreases, more shot can be placed in a standard shotshell.
  Labeling: The smaller the shot “number,” the larger the pellet diameter.
  Magnums: Shotshell marked as “magnum” means the shell has more shot or more gunpowder than a regular shell. Magnum and regular shotshells are interchangeable if the correct gauge and shell length are used.
• Steel shot pellets react differently than lead when shot. Steel weighs about 2/3 as much as lead but is much harder. Steel does not deform and is not as unstable in flight. It will produce a tighter pattern than lead shot. If using steel shot for hunting, choose a steel shot size one to two sizes larger than the lead shot you would select. See page 18 for more information about lead shot patterns and steel shot.
  

HOW A FIREARM WORKS

The same physical process is used to fire shotshells from shotguns or cartridges from rifles or handguns. Pulling the trigger causes the firing pin to strike and explode the primer in the base of the cartridge or shotshell. The spark from the primer ignites the gunpowder, which burns rapidly and converts to a gas. The gas rapidly expands and drives the projectile(s) through the barrel with great force.

How the rifle and handgun fire:

1. A cartridge is inserted into the chamber.
2. The action is closed, and the firing pin is pushed back and held back under spring tension.
3. The trigger is squeezed, releasing the firing pin, which moves forward with great force. The firing pin strikes the primer, causing it to explode.
4. The spark from the primer ignites the gunpowder. Gas converted from the burning powder rapidly expands in the cartridge.
5. The expanding gas forces the bullet out of the cartridge and down the barrel with great speed.
6. The rifling in the barrel (see page 16) causes the bullet to spin as it travels out of the barrel. The bullet’s speed and escaping gases produce a “bang.”

How the shotgun fires:

1. A shotshell is inserted into the chamber.
2. The action is closed, and the firing pin is pushed back and held back under spring tension.
3. The trigger is pulled, causing the firing pin to strike the primer producing a spark.
4. The spark from the primer ignites the gunpowder. Gas converted from the burning powder expands in the shell.
5. The gas pushes the wad against the shot; the wad and shot are forced out of the plastic body of the shell.
6. The wad and shot leave the barrel. The escaping gases produce a “bang.”
7. The shot and wad separate. The shot cluster spreads and forms a pattern.