12 Gauge Round

The 12 gauge shotgun shell is a type of ammunition in Fallout: New Vegas originally manufactured by Purebore before the Great War.

Gameplay
The Purebore Buckslayer "Shure Shot" 12 gauge shotgun shell is a large bore shotshell available in various buckshot loads and slugs. A specialized beanbag shell also exists, as well as coin shotshells. The add-on Gun Runners' Arsenal introduces five new varieties: 4/0 buckshot, 4/0 buckshot magnum, flechette, pulse slugs and fire damage-dealing dragon's breath shells.

Production
Standard buckshot, magnum buckshot, 4/0 magnum buckshot, coinshot and slug 12 gauge shotshell can be crafted at a reloading bench. A single shell requires the following ingredients:

Breakdown
Breaking down a standard 12 gauge shotgun shell yields:

Weapons using this ammunition

 * Hunting shotgun
 * Dinner Bell
 * Riot shotgun
 * Sawed-off shotgun
 * Big Boomer

12 gauge, bean bag
Bean bag rounds are less-than-lethal shotgun ammunition commonly used by law enforcement to quell riot situations. Bean bags inflict Fatigue Damage and stun a target momentarily. For soft targets, bean bag rounds can still drain their health and kill them with multiple shots.

12 gauge, coin shot
Coin shot is an improvised buckshot-like round using Legion Denarii as the projectiles. The end result is ammunition identical in damage to magnum buckshot round, but one which has a chance of leaving coins in targets it damages, as well as an extra "pellet" as shown by the damage indicator when using this type of ammunition. In V.A.T.S. Denarius can be seen leaving the barrel of the weapon in certain shots. Coin shot is regarded as better ammunition for trading, due to its dramatically increased value.

12 gauge, magnum
Magnum shells are standard buckshot shells with a higher powder load, increasing velocity, stopping power and -2 DT reduction. The downside is greater wear to a firearm due to the higher overall pressure, resulting in more regular maintenance.

12 gauge, slug
Slugs use only a single large, solid projectile, unlike shot, meaning weapon spread is traded for greater range and accuracy. These rounds also function as an armor-piercing round, as one powerful shot will deal more damage through a high DT than multiple weaker rounds.

12 gauge, 4/0 buck
A sub-type added with the new add-on Gun Runners' Arsenal, this shot sacrifices quantity for quality, with fewer, larger projectiles that pack a bigger punch.

12 gauge, 4/0 buck magnum hand load
A sub-type added with the add-on Gun Runners' Arsenal, these magnum shells use the larger 4/0 shot size, but with a greater powder load resulting in higher velocity, thus more firepower, at the cost of increased weapon wear due to the higher pressure generated.

12 gauge, dragon's breath
A sub-type added with the add-on Gun Runners' Arsenal, these zirconium-based pyrotechnic shells function as a short-ranged flamethrower, having an incendiary effect on targets for 5 seconds; hence the name "dragon's breath".

12 gauge, flechette
A sub-type added with the add-on Gun Runners' Arsenal, these shells have had their traditional shot replaced with tiny metal darts that are great for armor penetration but are not quite as damaging. Flechette rounds also greatly decrease muzzle flash, allowing for more accurate aiming.

12 gauge, pulse slug
A sub-type added with the add-on Gun Runners' Arsenal, these slugs cause more damage to robots and enemies wearing power armor, and the target gets an extra kick from an electromagnetic pulse triggered by the impact.

Locations

 * Sold by Alexander, the Vendortron, Blake, Daniel Contreras and the Arms Merchant, among others.
 * Can occasionally be found on NCR heavy troopers.
 * Occasionally found on Centurions and Prime legionaries.
 * Sometimes found on Great Khans.
 * Sold by Joshua Graham in large quantities.

Behind the scenes
According to Joshua Sawyer, the implementation of coin shot was a play on old western myths about "putting shells full of dimes in shotguns." It was further inspired by the movie Pat Garrett and Billy the Kid, in which actor Kris Kristofferson uses a double-barrel shotgun filled with dime shot.

Bugs

 * Although 12 gauge bean bag ammunition specifies that it causes 250 points of fatigue damage, in practice each shot will only induce 50 points of fatigue. Furthermore, all shotguns inflict a minimum of 12.25 points of damage, regardless of damage penalties or effects of Damage Threshold or Damage Resistance. These two issues mean that attacking a target with bean bag shells will most likely result in the target's death before it is ever knocked out due to Fatigue.
 * Additionally, bean bag shells can inflict fatigue damage on robots, something which the boxing gloves and Golden Gloves specifically avoid. This makes it possible to "knock out" robots, most of which can endure no more than 100 points of fatigue before being rendered unconscious.
 * 12 gauge slug shells have a listed 30% chance of dropping an empty hull, but they do not actually reference the 12 gauge hull item, so they don't actually provide 12 gauge hulls.