"An old-fashioned shotgun. Doesn't hold much ammo, but packs quite a punch."
— Inventory description
The M21 Shotgun (ショットガンM21 shottogan M 21 ) is a weapon that appears in Resident Evil 7: Biohazard. It is one of three shotguns in the game, the others being the M37 Shotgun and Thor's Hammer, the latter being a minigame exclusive.
Initially the Broken Shotgun, it is used as a placeholder until the player finds the Model Shotgun. The player can repair the Broken Shotgun by combining it with a Repair Kit; either very early on by sacrificing the M37 Shotgun and Broken Handgun, or much later without sacrificing the other 2 weapons' availability.
A classic over-under break-action shotgun; holding only 2 shells compared to the M37 Shotgun but offers more firepower per shell, heavier knock back power, and concentrated blast ergo better effective range. Takes up 2 inventory slots.
Its heavier knock back power compliments the P19 Machine Gun well for mid range sustained engagement.
In Nightmare, the M21 Shotgun is made available to craft for 200 Scrap after the player unlocks the "M21 Shotgun" reward by accumulating 4,000,000 Points. The "Shotgun Upgrade" Skill affects this weapon.
Ethan Must Die
In Ethan Must Die the M21 Shotgun can be a random drop from 2 Star ranked boxes.
Jack's 55th Birthday
In Jack's 55th Birthday, the M21 Shotgun is available in the Item Box during the stage "Testing Area 1". There also one located under the Pantry during "Main House 1" which can only be accessed through the Laundry Room.
End of Zoe
In End of Zoe, the M21 Shotgun is unlocked by beating the game on Easy or Medium Difficulty, and will become available by opening the item box. On Medium difficulty, you start with 7 shells (2 already loaded into the gun and 5 extra appearing in the item box with it) while on the Joe Must Die difficulty you only start with 2.