The 6mm BR Remington cartridge is based a necked down.308 × 1.5 Barnes cartridge which in turn is based on the.308 Winchester case shortened to.
The 6mm BR Remington cartridge is based a necked down.308 × 1.5 "Barnes cartridge. These necked down.308 × 1.5" Barnes cartridge in turn is based on the.308 Winchester case. This.308 Winchester case is shortened to.