Originally Posted by driftrider

It's probably a .257 Roberts or a .257 Weatherby Mag (opposite ends of the quarter bore spectrum, but both will certainly do the job on deer). There is no .237 caliber. And don't worry about it. You're learning. If you want to really melt your brain, consider that the .38 Special and .357 Magnum cartridges both use the same diameter bullet. Or that the .44 Magnum is actually a 43 caliber (0.429-.430").

Mike