20 Gauge Round

 is a type of ammunition in Fallout: New Vegas.

Characteristics
20-gauge shotgun shells are very similar to their better known cousin, the 12 gauge shotgun shells. 20-gauge shells are a plastic tube with a brass base. The primer, gun powder, and wadding are compressed into the bottom of the casing and the projectiles are place on top, held by the plastic tubing. Most common projectiles are small lead or steel balls called shot. Being smaller than 12-gauge shells (smaller numbers mean bigger in "gauge" speak) 20-gauge shells include less powder and less shot. The benefit the the smaller shell size is less "kick" when fired.

20 Gauge, Magnum
A magnum shell would include more grains of gun powder, thus increasing the velocity the the projectiles when fired.

20 Gauge, Slug
In a slug version of a shotgun shell a single large sabot is used in place of the shot.

Used in

 * Sturdy caravan shotgun
 * Caravan shotgun
 * Lever-action shotgun
 * Single shotgun

Appearances
only appears in Fallout: New Vegas.