Just wondering if anyone has ever necked down the .257 Roberts (or 6mm Remington or 7x57 Mauser as they are all based on the same case) to .22 caliber? I guess there is no reason for it as it would probably perform about the same as the .22/250. It might even be closer to the .220 Swift. But if anyone did, the brass would be easy to make out of 6 mm brass. It might, however, be an interesting experiment if no one has ever done it.