The 20×110mm USN (also known as 20×110mm US Navy and 20mm Mk-100 Series) is an autocannon cartridge developed by the US Navy after World War II for use in Mk 11 and
Mk 12 autocannon
An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bull ...
s. They are called the ''Mk 100'' series as they range from Mk 101 to Mk 109.
It has the same rim diameter as the
20×102mm
20 mm caliber is a specific size of popular autocannon ammunition. It is typically used to distinguish smaller-caliber weapons, commonly called "guns", from larger-caliber "cannons" (e.g. machine gun vs. autocannon). All 20 mm cartridges ha ...
but a different length and contour. It is not interchangeable with any other 20×110mm cartridge.
Available loads
Some of the available loads for the 20×110mm USN are as follows:
There is also a cartridge, 20 mm, dummy, Mk 103 Mod 0 (USN) which is an inert round. It has an empty primer pocket and holes in the case or a plugged primer pocket. It may be empty or filled with inert material. The projectile is usually brass or bronze plated.
References
{{DEFAULTSORT:20by110mm USN
Large-caliber cartridges