Shotgun cartridge

Shotguns typically use a smoothbore barrel with a tapered constriction at the muzzle to regulate the extent of scattering.

Other unusual projectiles such as saboted flechettes, rubber balls, rock salt and magnesium shards also exist.

Waterglass (sodium silicate) was commonly used to cement the top overshot wad into these brass casings.

Some companies have produced what appear to be all-plastic shells, although in these there is a small metal ring cast into the rim of the cartridge to provide strength.

The brass does not provide a significant amount of strength, but the difference in appearance gives shooters a way to quickly differentiate between high and low powered ammunition.

Cushions are almost universally made of plastic with crumple zones, although for game shooting in areas grazed by farm stock or wildlife biodegradable fiber wads are often preferred.

The bigger 10-gauge, once popular for hunting larger birds such as goose and turkey, is on the decline with the advent of the longer, "magnum" 12-gauge cartridges, which offer similar performance.

Commonly used by hikers, backpackers and campers, snake shot is ideally suited for use in revolvers and derringers, chambered for .38 Special and .357 Magnum.

The .45-70 "Forager" round, which contained a thin wooden bullet filled with birdshot, was intended for hunting small game to supplement the soldiers' rations.

Garden guns are short-range weapons that can do little harm past 15 to 20 yards, and they are quiet when fired with snake shot, compared to standard ammunition.

These guns are especially effective inside of barns and sheds, as the snake shot will not shoot holes in the roof or walls, or more importantly injure livestock with a ricochet.

[11] In 1976, the United States Fish and Wildlife Service took the first steps toward phasing out lead shot by designating steel-shot-only hunting zones for waterfowl.

In the 1970s, lead-free ammunition loaded with steel, bismuth, or tungsten composite pellets instead of more traditional lead-based shot was introduced and required for Migratory Bird Hunting (Ducks & Geese).

As a result, the measurement of pellet velocity is also an additional obligation for cartridges in 12-, 16-, and 20-gauges in both standard and high performance versions sold in Europe.

This poses a major hazard at indoor ranges or whenever metal targets or hard backstops (e.g. concrete wall vs. a dirt berm) are used.

Any shooters who are considering to buy ammo loaded with steel for anything other than hunting purposes should first find out if using it will not cause undue hazard to themselves and others.

[citation needed] However, data supporting the danger of firing high velocity cartridges loaded with steel shot causing barrel wear has not been published and the US equivalent of CIP, SAAMI, does not have any such restrictive limitations on the velocity of commercial steel shot cartridges sold in the United States.

To make matters more complex, there are small differences in the size of American, Standard (European), Belgian, Italian, Norwegian, Spanish, Swedish, British, and Australian shot.

Australia has a hybrid system due to its market being flooded with a mixture of British, American, and European cartridges.

Shot of these sizes is used in specialized cartridges designed to be fired at close range (less than four yards) for killing snakes, rats and similar-sized animals.

Larger sizes of shot, big enough that they must be carefully packed into the cartridge rather than simply dumped or poured in, are called "buckshot" or just "buck".

Buckshot is used for hunting medium to large game, as a tactical round for law enforcement and military personnel, and for personal self-defense.

Reduced-recoil 00 buckshot is often used in tactical and self-defense rounds, minimizing shooter stress and improving the speed of follow-up shots.

Other rounds include: Most modern sporting shotguns have interchangeable choke tubes to let the shooter change the spread of shot that comes out of the gun.

One improvised method for achieving the same effect involves pouring molten wax or tar into the mass of shot.

[19] This can be dangerous, as it is thought to cause higher chamber pressures—especially if part of the cartridge remains behind in the barrel and is not cleared before another shot is fired.

[15] Another less important dimension of spread concerns the length of the in-flight shot string from the leading pellet to the trailing one.

The use of multiple pellets is especially useful for hunting small game such as birds, rabbits, and other animals that fly or move quickly and can unpredictably change their direction of travel.

A secondary impact of this equivalence was that common cartridges needed to stay the same size, physically, e.g., 2+1⁄2 or 2+3⁄4-inch shells, in order to be used in pre-existing shotguns when smokeless powder started being in the place of black-powder.

Initially, this meant that increased numbers of over-powder card wads had to be stacked to achieve the same stack-up length.

A 12-gauge shotgun cartridge in a transparent plastic hull, allowing the contents to be seen. From left to right: brass, propellant, over-powder wad, shot wad, #8 birdshot, over-shot wad, and crimp
A 1908 depiction of a shotgun cartridge, showing a simple felt wad used to separate the powder (left) and shot (right)
Shotgun cartridge comparison (left to right): 12-gauge, 20-gauge, 16-gauge, 28-gauge, and .410 bore
M35 .410 shotgun cartridges for M-6 survival gun w/.22 long rifle for comparison
CCI .22LR snake shot loaded with #12 shot
Military Issue .45 ACP M15 "shot shell" on the far right.
Lead shot
12-gauge birdshot cartridge.