.25-06 Remington
The .25-06 Remington had been a wildcat cartridge for half a century before being standardized by Remington in 1969. It is based on the .30-06 Springfield cartridge necked-down (case opening made narrower) to .257 caliber with no other changes. Nominal bullet diameter is 0.257, and bullet weights range from 75 to 120 grains (4.9 to 7.8 g).