Two bore or 2 bore is a mostly obsolete firearm
caliber
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matc ...
.
Specifications
Two bores generally fire spherical balls or slugs of hardened lead or, in the modern metallic cartridge, additionally a solid bronze projectile. The nominal bore is , and projectiles generally weigh 8
ounce
The ounce () is any of several different units of mass, weight or volume and is derived almost unchanged from the , an Ancient Roman unit of measurement.
The avoirdupois ounce (exactly ) is avoirdupois pound; this is the United States customa ...
s (227
gram
The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram.
Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to th ...
s; 3500
grains
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legumes ...
). The velocity is relatively low, at around at the muzzle, but develops approximately muzzle energy.
History and background
Despite the popularity of the calibre in modern gun lore there is no evidence the 2 bore as named was actually used as a terrestrial and shoulder fired firearm. The equivalent calibre size equates to various punt guns used for harvesting large number of waterfowls usually mounted in 'punts' or flat bottomed boats for commercial purposes. A common misconception is the hunter
Sir Samuel White Baker being attributed to its use, however his firearm 'Baby' as described below was actually close to 3 bore, the firearms records still exist by the maker listing the serial number as 1296. The confusion occurs due to Baker's common reference to the projectile fired from the firearm weighing 'half a pound', which would if a round ball equate to a 2 bore by definition. However Baker himself never refers to this projectile being a round ball nor uses the term 2 bore in any of his writings, indicating this half pound shell was a longer projectile of cylindrical or conical shape.
Schroeder & Hetzendorfer cartridge
See also
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4 bore
Four bore or 4 bore is a mostly obsolete black powder caliber of the 19th century, used for the hunting of large and potentially dangerous game animals. The specifications place this caliber between the larger two bore and the lesser six bore. Thi ...
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Gauge (bore diameter)
The gauge (or commonly bore in British English) of a firearm is a unit of measurement used to express the inner diameter (bore diameter) of the barrel.
Gauge is determined from the weight of a solid sphere of lead that will fit the bore of the f ...
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Holland & Holland
References
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{{DEFAULTSORT:1326 in
Firearms by caliber
British firearm cartridges