4.5×26mm MKR

The 4.5mm MKR cartridge was a prototype Swedish rifle cartridge.

History
The 4.5mm MKR was originally developed by Interdynamic AB, a Swedish company, in the 1980s.

Due to concerns about stopping power and problems with using rimfire ammunition the MKR project was abandoned at the prototype stage and thus the 4.5mm mkr never saw service or any kind of widespread use.

Design
The 4.5mm MKR was essentially a .22 WMR necked down to a 4.5mm bullet, designed to be used in the Interdynamics MKR rifle.

Specifications

 * Bullet width: 4.5mm (.177 in)
 * Bullet weight: 1.58 g (24.4 gr)
 * Muzzle velocity: 1,000 m/s (3,270 ft/s)