20 × 99 mm r

20 × 99 mm r
general information
caliber	20 × 99 mm r
Sleeve shape	Rim cartridge
Dimensions
Floor ⌀	20 mm
Sleeve length	99 mm
Weights
Bullet weight	91-99 g
Technical specifications
Speed v 0	750-790 m / s
Lists on the subject

The 20 × 99 mm R is a cartridge that was put into service with the Soviet armed forces with the SchWAK around 1936 and is also known with the designation "WW2 ShVAK, Berezin, Helenius rifle".

Original case in caliber 12.7 × 108 mm R

It arose from the idea that only the barrel of a weapon should be changed in order to be able to fire a different caliber. The base for the 20 × 99 mm R was a case from the 12.7 × 108 mm R cartridge, which was expanded and shortened to accommodate a 20 mm bullet.

The 20 × 99 mm R caliber was used during World War II and into the 1960s. It has now been replaced by more modern calibers; however, the Finnish company Helenius still offered rifles RK20 and RK99 Mk2 in this caliber in the early 2000s.

Types of ammunition

OS

Incendiary bullet

EAST

Incendiary bullet with tracer

OF

Explosive projectile - fragmentation effect

OFS

Explosive projectile - fragmentation effect, incendiary capsule

BS

Armor piercing

BST

Armor piercing with tracer

PU

Practice ammunition

PUT

Practice ammunition with tracer

Individual evidence

↑ ^a ^b 20 MM CALIBER CARTRIDGES, at quarry.nildram.co.uk ( Memento from August 21, 2007 in the Internet Archive )
↑ ^a ^b 20 x 99 R round (Russian Federation), Cannon - 20 to 30 mm cannon, at janes.com ( Memento from January 25, 2011 in the Internet Archive )

[Nr.1-1] 20 MM CALIBER CARTRIDGES, at quarry.nildram.co.uk ( Memento from August 21, 2007 in the Internet Archive )

[Nr.2-2] 20 x 99 R round (Russian Federation), Cannon - 20 to 30 mm cannon, at janes.com ( Memento from January 25, 2011 in the Internet Archive )