Artillery is a class of large military weapons built to fire munitions far beyond the range and power of infantry's small arms.
Ernst Martin Axel Welin (10 November 1862 – 27 July 1951), was a Swedish inventor and industrialist.
A breech-loading gun is a firearm in which the cartridge or shell is inserted or loaded into a chamber integral to the rear portion of a barrel.
A cartridge is a type of firearm ammunition packaging a projectile (bullet, shots or slug), a propellant substance (usually either smokeless powder or black powder) and an ignition device (primer) within a metallic, paper or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting.
In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
A rifled breech loader (RBL) is an artillery piece which, unlike the smooth-bore cannon and rifled muzzle loader (RML) which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun.
A screw is a type of fastener, in some ways similar to a bolt (see Differentiation between bolt and screw below), typically made of metal, and characterized by a helical ridge, known as a male thread (external thread).
The Welin breech block was a revolutionary stepped, interrupted thread design for locking artillery breeches, invented by Axel Welin in 1889 or 1890.