.45 Auto

 is a type of ammunition manufactured by Union Cartridge in the Fallout: New Vegas add-on Honest Hearts.

Characteristics
After the completion of Honest Hearts the ammo type will also begin appearing in the main game, sold by Vendortron at the Gun Runners' kiosk, Cliff Briscoe in the Dino Bite gift shop, Quartermaster Bardon at Hoover Dam, Johnson Nash in Nash residence, and traveling merchants.

Weapons using this ammunition

 * .45 Auto pistol
 * A Light Shining in Darkness
 * .45 Auto submachine gun

.45 Auto, +P
.45 auto, +P (Over-pressure) is an ammunition designed to fire at a higher internal pressure than standard ammunition to ensure higher velocity, stopping power and a slight Armor Piercing ability but at the cost of requiring more maintenance than usual. This ammunition can be bought at most vendors in small quantities. It can also be made at a reloading bench.

.45 Auto, Hollow point
.45 Auto, Hollow points is an ammunition manufactured by Federal Cartridge corporation and designed to mushroom and break up on impact, causing massive trauma on fleshy, unarmored targets. However, this also means they break up when they hit things like armor plating, drastically reducing the weapon's penetrating power.

.45 Super (Hand Load)
.45 Super is an ammunition load manufactured by Southern Cartridge company and designed for much higher pressures than the gun was originally intended to fire. Muzzle velocity is 20% greater than even +P resulting in much better armor penetration and damage, but causing considerable weapon damage to guns not specially designed to operate these "Wildcat" rounds.