The ARWEN 37
The ARWEN 37 is a rotary-drum 37mm police Grenade Launcher originally designed for non-lethal use. It carries 5 rounds.
In Resident Evil
Featured in both Resident Evil and Resident Evil: Director's Cut as the "Bazooka" (or as the "Grenade Gun" in Japanese releases), as well as Remake, Resident Evil 0 and Resident Evil: The Umbrella Chronicles.
In the Remake, the ARWEN has been modified with an AR-style lower receiver assembly, selector, and a four-position collapsible stock. It is Forest's custom weapon of choice.
Although the real life ARWEN 37 is a non-lethal weapon, in Resident Evil this weapon is quite lethal and can usually be loaded with various types of rounds; from basic Grenade rounds to more dangerous rounds such as Acid and Incendiary. It also holds one more round than its real life version. This weapon is also used by Jill Valentine in Marvel vs. Capcom 2.
In the Remake, there is a useful glitch that involves the Grenade Launcher, that you can get more than 250 Rounds with any set of Grenade Rounds, using the Item Box. This is best used on Incendiary Rounds because killing a zombie would burn it preventing it from turning into a Crimson Head. This is confirmed to only work on the NTSC version, as it appears that the PAL version is fixed on this version for the GC.