Two bore or 2 bore is an obsolete firearm caliber.
Specifications
Two bore firearms generally fire spherical balls or slugs made of hardened lead, or in the case of a modern metallic cartridge with either solid brass or bronze projectiles. The nominal bore is , and projectiles generally weigh 8 ounces (227 grams; 3500 grains). The velocity is relatively low, at around at the muzzle, but develops approximately muzzle energy.Dickson, J. (2019, August 14). The tyrannosaurus 2-bore: Most powerful sporting rifle. Firearms News. https://www.firearmsnews.com/editorial/tyrannosaurus-2-bore-rifle/365185S&H Super PrecisionTM. Schroeder & Hetzendorfer LLC. (n.d.). http://www.2-bore.com/home.html
According to William Wellington Greener, the Eley Brothers Limited company produced 2 bore paper cases, but the bullet caliber and power charge—and subsequently performance—were practically equivalent of a thin brass-cased 4 bore cartridge, while being less waterproof.
History and background
2 bore guns were manufactured for hunting waterfowl, but due to their weight and hefty recoil, hunters preferred using smaller guns, such as single-barreled 4 bore or double-barreled 10 bore guns, or 12 gauge shotguns.
Before the advent of Nitro Express cartridges in 1898, ivory poachers used large caliber elephant guns ranging from 2 to 4 bore that could weight up to and were carried by a team of porters and fired solid lead balls; These were the only suitable weapons for big-game hunting as existing black powder rimfire cartridges were barely adequate for medium-sized game and firearm locking systems weren't capable of withstanding the pressure generated by high-powered cartridges. While some authors— including W. D. M. Bell—describe Sir Samuel Baker's "Baby" rifle as a 2 bore, author Terry Wieland describes the Baby as a 3 bore rifle that fired a 5 oz (140 g, 2,200 gr) shell.
According to an anonymous account from an English mercenary who served with the Transvaal Republic, during a border skirmish with Swaziland, the opposing side employed a team of three men to operate a single 2 bore elephant gun, which reportedly caused several casualties in the Boer ranks:
Schroeder & Hetzendorfer cartridge
See also List of rimmed cartridges 4 bore Gauge (bore diameter) Holland & Holland
References