This priming tool is from the early 1930s when Remington made 257 Remington and Winchester made 257 Roberts so as not to stamp REMINGTON on their barrels. The Rem name was dropped soon after. Both companies used the Remington design with identical cases with steeper shoulder angle than on the original Ned Roberts design. This appears to be a modified #3 tool, the screw in primer seater is marked 2 on the back. An unusual reloading tool from the Ideal company. Free shipping.