The Magnum Revolver is an unlockable weapon featured in Resident Evil 0. It appears as a large five shot stainless steel revolver with wood grips.
The weapon itself is used by Billy to deliver the final shot to the Queen Leech before it is destroyed by the sunlight. This all occurs in a cutscene, it is not actually found and used as part of gameplay in this manner.
The Magnum Revolver is unlocked upon completion of the Leech Hunter minigame with an B Rank which means the player must have collected 90-99 Leech Charms. Once unlocked, the weapon will appear in the train in Second Class private room A. Once Leech Hunter is completed with a A Rank (all 100 Leech Charms gathered), the Magnum will have unlimited ammo along with the rest of the weapons.
The Magnum Revolver holds 5 rounds at a time and uses the rare Magnum Ammo. It does incredible damage (inflicting much more damage than the regular magnum) and bullets pierce through enemies hitting other enemies behind them. Rebecca will be forced to take a step back after firing the weapon. Billy will stand his ground while firing and can fire it faster than Rebecca.
- Examine: Magnum Revolver
"A magnum revolver containing enhanced parts like a new cylinder and frame. Its tremendous firepower makes it more of a "hand cannon" than a handgun."
The Umbrella Magnum Revolver Development Story (アンブレラ・マグナムリボルバー開発ストーリー), is an article written by Capcom Japan. It revealed the origins of the RE0 Magnum Revolver, referred to as "Umbrella Magnum".
According to the story, the Magnum was developed as a researcher's defensive weapon against B.O.W.s., after smaller caliber weapons failed to effectively stop these threats.
Tanaka Works, a Japanese airsoft company, has manufactured six inch & eight inch barrel airsoft versions of the RE0/Umbrella Magnum. The guns have the Umbrella Corporation's medallion placed on the grips.