M45 shotgun

The M45 Tactical Shotgun, formally known as the Tactical Shotgun, 8 Gauge, Pump Action, M45, is a shotgun used by the United Nations Space Command Army.

Design details
The M45 Tactical Shotgun is a special-purpose weapon used in any situation where the range of engagement is limited and when over-penetration is not desirable, but maximum stopping power is required. Like the M90 Close Assault Weapon System, the M45 is a pump-action, magazine-fed (dual tubular, non-detachable type) weapon that uses 8 gauge magnum (3.75”) ammunition. It features an adjustable stock, however this is purely cosmetic in-game.

Gameplay
In gameplay, the M45 Tactical Shotgun is more powerful than the M90 Close Assault Weapon System from Halo 3 and Halo 3: ODST. The pellets have a tighter grouping and the range is superior as well, which also makes it harder to hit multiple enemies at close range. Although this change is hardly noticeable, impact force can be noticed as damage is higher.

The shotgun is very powerful in small confined maps. It should be used as a "corridor sweeper" because of its extreme damage at close range. When you are carrying this weapon people will mark you out as an important target due to the fact that you control a power weapon.

Trivia

 * It is possible that Bungie named this shotgun the M45 because it is the in-game counterpart to the M90 from the other games: 45 is half of 90.
 * In the Halo: Reach Multiplayer Beta, the shotgun had cyan lights similar to those on the M90 in Halo: Combat Evolved and Halo 3. The sights are red in the final game.
 * The M45 is the weapon of choice for Spartan-III Emile-A239.
 * The M45 pumps at the end of every reload animation. In reality, doing this when the weapon isn't empty would eject an unused shell.
 * In the Halo: Reach strategy guide, the silhouette used to mark shotgun spawns points on multiplayer maps appears to be missing their stocks. However, the M45 with the collapsible stock does not appear in the final version of the game.
 * When a Sangheili character draws this weapon, they will cycle the action. In reality this would cause a chambered round to be ejected, this could be explained that because only rarely do Sangheili use human weapons, they may be unskilled in operating them, or it might simply be an oversight on Bungie's part.

List of appearances

 * Halo: Reach