12 gauge

12 Gauge is an size description for ammunition used in shotguns.

The only type of 12 Gauge ammunition available in Fallout, Fallout 2, Fallout 3 and Fallout: Brotherhood of Steel is 12 Gauge Shotgun Shells.

Fallout Tactics had a variety of 12 Gauge ammunition, including 12 Gauge Shotgun Shells, 12 Gauge EMP Shells, 12 Gauge Flechette, 12 Gauge Rubber and 12 Gauge Slug Shells.

Weapons Using 12 Gauge Ammunition

 * Combat Shotgun
 * H&K CAWS
 * Pancor Jackhammer
 * Sawed-Off Shotgun
 * Shotgun

Described
"Gauge" is used to describe the bore size of a shot-firing weapon. Although bore sizes range incrementally from 1.5 up to 32 (with an aberrant 67.5 topping the scale), 10, 12, and 20 gauge are the most common bore sizes, with 12 gauge leading the group in popularity. Most civil, police, and military shotguns are 12 gauge weapons. A 12 gauge shotgun has a bore size of 18.53mm (.729", or 72 caliber).

Sizes of shot - the individual lead or steel pellets that are fired from the weapon - vary as well. The most common combat load is 00 Shot, pronounced "double-aught." A typical 12 gauge shotgun shell loaded with 00 Shot contains nine to fifteen pellets (nine for standard, 12 or 15 for magnum shells). Each pellet is 8.4 mm in diameter (0.33" or 33 caliber) and weighs 3.45 grams.