Mercy

Mercy is a unique 40mm grenade machinegun

Gameplay
Its higher damage comes at the cost of using 40mm grenades, which are less common and more expensive than the 25mm grenade used by the standard grenade machineguns. The larger size of the 40mm grenades also restricts its ammunition capacity to 18 grenades, 12 fewer than the regular grenade machinegun. The 40mm grenade is also heavier than its 25mm counterpart. Like most unique weapons, Mercy cannot be modded.

Durability
Mercy can fire a total of about 2495 standard rounds, the equivalent of 139 reloads, from full condition before breaking.

Variants

 * Grenade machinegun

Location
Dead Wind Cavern - By a dead Brotherhood of Steel paladin along with some 40mm grenades, 40mm incendiary grenades and T-45d power armor and helmet. It is guarded by various types of deathclaws and the legendary deathclaw.

Behind the scenes
The writing on the "display" is part of a Bash script, a scripting language that is used for UNIX and UNIX-like operating systems like Plan9, Linux, BSD, Darwin, or MacOS. The script that the display shows seems to be a repeated conditional that prints an error, prints the correct usage, then exits with an error.

Bugs

 * The game may crash if you fire continuously in the same place.
 * The weapon can disappear from your game.