User:Vjaarland/Sandbox4

6.5×45mm MASSOR
Type	Rifle
Place of origin	Valduvia
Service history
In service	1956–present
Used by	MASSOR and others
Wars	Burland conflict Miersan War
Production history
Designer	Valduvian Workers' Army
Designed	1953
Produced	1954–present
Specifications
Case type	Rimless, bottleneck
Bullet diameter	6.70 mm (0.264 in)
Neck diameter	7.50 mm (0.295 in)
Shoulder diameter	10.90 mm (0.429 in)
Base diameter	11.30 mm (0.445 in)
Rim diameter	11.30 mm (0.445 in)
Rim thickness	1.50 mm (0.059 in)
Case length	45.00 mm (1.772 in)
Overall length	68.00 mm (2.677 in)
Case capacity	2.79 cm3 (43.1 gr H2O)
Rifling twist	200 mm
Primer type	Large rifle
Maximum pressure	430.00 MPa (62,366 psi)
Ballistic performance
Bullet mass/type Velocity Energy 8.0 g (123 gr) 840 m/s (2,800 ft/s) 2,935 J (2,165 ft⋅lbf)
Test barrel length: 610 mm

The 6.5×45mm MASSOR, also known as 6.5×45mm Valduvian or simply 6.5×45mm, is a rimless bottlenecked intermediate rifle cartridge developed in Valduvia during the 1950s. It has been the standard service rifle chambering for the Valduvian Workers' Army since 1956, and was originally designed to be used in the TBA assault rifle. The cartridge was adopted as the standard for MASSOR upon the organization's establishment in 1999, and now enjoys widespread use among the armed forces of its member states. It is commonly used in the Lielstraupe TŠ-90 and TBA assault rifles, as well as the TBA light machine gun.

The Valduvian Workers' Army developed the 6.5×45mm cartridge after the Valduvian-Weranian War, which revealed the need for a more modern weapon to replace the Land Component's aging Š-31 straight-pull bolt-action rifles. Impressed by the battlefield performance of the Weranian StG 44, the military laid out requirements for a selective fire rifle capable of accepting a detachable magazine of at least 20 rounds. The new rifle would require a lighter and less powerful chambering to replace the full-powered 7.5×55mm cartridge, allowing each soldier to carry more ammunition and maintain control over the weapon in full automatic. However, the military also required that the new cartridge be able to make effective shots out to 1,000 meters, allowing it to also be used in sniper rifles and general-purpose machine guns as well.

The new cartridge was adopted alongside the TBA assault rifle in 1956, and almost immediately saw combat with Valduvian security forces during the Burland conflict. The Valduvian government exported the cartridge to other socialist states and movements beginning in the 1960s, and was notably used by East Miersan forces during the Miersan War. In 1999, the cartridge was standardized by MASSOR to be the universal service rifle chambering for its member states.