Remington released the commercial .257 Roberts in 1934. The original cartridge was designed by N.H. Roberts (a well-known experimenter and gun writer during the 1920s and 30s) and was based on the 7x57mm Mauser necked down.
The .257 Roberts has been called the “most useful rifle cartridge ever developed.” It’s suitable for a range of hunting under many conditions. As a long-range varmint cartridge, it’s as good as they come — only slightly inferior to newer 6mms. On deer, antelope, black bear, sheep, or goat, it’s as good as any other cartridge. Naturally, it’s not as powerful as the .270 Win. or .30-06 but has ample power for the game mentioned at all practical ranges.
Ammunition companies underloaded the .257. However, in the late 80s, higher pressure +P loads were…