Hellsing ARMS Casull

The Hellsing ARMS .454 Casull Auto, sometimes shortened to Casull, is a semi-automatic handgun that is one of Alucard's favorite weapons of choice. The engraving on the frame of the gun (Hellsing ARMS 000001) indicates that it is the first custom weapon ever made by Walter C. Dornez.

Profile
The Casull is a classical semiautomatic handgun, based on pre-WWII handgun designs by Colt, most notably Colt's popular handguns, the M1911 and the M1903. It weighs approximately 6 kg unloaded and has a magazine capacity of six (plus one in the chamber) .454 Casull cartridges.

The overall design of the Casull is simple, using the Browning short recoil mechanism. Its most recognizable feature is its long slide, counteracting the weapon's heavy recoil with its weight. The barrel is 10 inches long (specified on the slide) and finished with titanium nitride which gives it a characteristic gold color.

Usage
In both the anime and the manga, when the Casull fails to kill Anderson, Alucard specifically asks Walter for "something bigger" (however, it must be noted that he may have been referring to the ammunition). Despite its inability to seriously wound Anderson, it is too heavy and unwieldy for a human to use, yet a perfect match for Alucard's strength. It fires custom-made explosive .454 Casull rounds, with the steel bullets bearing a core made from the melted silver Christian cross from Lancaster Cathedral. However, when Alucard first introduces the gun in Volume 1 while dealing with the vampire in Cheddar, he says that it fires 13mm rounds. A possible explanation would be that the gun was originally chambered in .454 Casull, but now fires a custom round necked up to 13mm, as the casings shown ejected by the pistol are bottle-necked and rimless, while the commercial Casull round uses a straight walled rimmed case.

Bullets and Rounds
Even though Alucard has stated that the round uses explosive silver bullets, the traits exhibited by the bullet wounds show that it displays characteristics similar to that of a full metal jacketed pistol round, when it punches through the lung of two people without having the round explode. The weapon most likely has a single-stack magazine meaning a capacity of 7 rounds as seen in other .45-caliber handguns with single-stack magazines such as the M1911 and SIG P220, and as seen from Alucard's battle with Luke Valentine in Volume 2, where he fires 7 rounds at Luke before the slide clicked back on empty. There is no official magazine capacity.

Although Alucard has reloaded it at many points throughout both the manga and anime, Hirano has joked in the back of volume 1 that "They're all cosmoguns that can hold a million rounds". This is also evidenced in the first OVA, where Alucard takes out a large group of ghouls without reloading.

Known users
From the 1980s thru 2001 two gun makers made auto mag hand guns that used the .45 Winchester magnum round. The win mag round has very similar size to the .454 casull, if casull were to make an auto. L.A.R grizzly .45 Winchester magnum was the first, made from 1983-1999. Made as the first and most powerful auto handgun in the world. Main use was as a backup gun for bear hunting. Could take down a grizzly in one shot. They even made one with a 10" barrel! That makes the gun almost 14" long! AMT made the automag IV chambered in .45 win mag from 1992-2001. The L.A.R. 10" barrel looks very similar to Alucards gun. With some engraving and duracoat you could make it look almost exactly like his, and it would be a real world working hand gun. I think they made just under 200 in the 10" barrel. They are going for around $2,500.
 * Alucard

Trivia

 * When used in conjunction with the Jackal, the Casull gives Alucard an appearance similar to Dante, the protagonist of the Devil May Cry series. Both are red-clad transhumans (a vampire and a half-demon, respectively) who wield a white and a black gun simultaneously (Casull and Jackal for Alucard, Ebony and Ivory for Dante). However the two pairs of guns vary vastly in stopping power as Dante's pistols are chambered in .45 ACP and powered by Demon energy to shoot rapid barrages w/ infinite ammo.
 * Along with other references, such as Seras's Harkonnen, the use of Casull and Jackal may be a reference to the antagonists of Frank Herbert's novel Dune--specifically, the Harkonnen custom of wielding a poisoned long knife with a black glove in the right hand and a short knife with a white glove in the left.
 * "Casull" is not the actual name for the pistol itself. It is the name for the round used by the gun, .454 Casull Auto.
 * It made its final appearance in OVA 8, its fate is unknown after that.
 * The rounds fired by the Hellsing Arms .454 Casull Auto is a rimless cartridge. Since the .454 Casull (not to be confused with the .454 Casull Auto from the manga and anime) is a rimmed cartridge designed to be used in revolvers in real life it can be confirmed that the round that the Hellsing Casull fires only exists in the manga and anime since no rimless .454 Casull exists. Therefore it can be assumed that the .454 Casull Auto uses the same bullet from the .454 Casull cartridge and the casing is a proprietary design made by Hellsing Arms.
 * The .454 Casull Auto and the end of the name indicates that the cartridge is a modified .454 Casull designed to load in semi-automatic pistols. The auto at the end of many real firearm cartridge nomeclature does not mean automatic fire, it stands for auto-loading.
 * Despite the slide reading .454 (roughly 11.23mm) Alucard specifically names the rounds as 13mm. This could be due to a higher caliber barrel being fitted for the gun, or a misinterpretation, as the rim diameter of the .454 casull is 13mm.