.224 in (5.7 mm)
| United States|
| ~1963, standardized 1978|.22 BR Remington Wikipedia
The .22 Bench Rest Remington cartridge, commonly referred to as the .22 BR Remington, is a wildcat cartridge commonly used in varmint hunting and benchrest shooting. It is based on the .308×1.5-inch Barnes cartridge, necked down to .22 caliber, lengthened by .020 inches and with the shoulder angle increased to 30°. It was first developed in approximately 1963 by Jim Stekl, and in 1978 Remington standardized the dimensions. It is renowned for its high velocities and excellent accuracy.