I've been doing the same as PintsofCraft was doing in his thread, "Lee Collet & FL used w/o expander - any benefit?"

mathman suggested .....



My question is for the 257 Roberts. Which FL die would be suitable to use as a body die for the 257 Roberts?

I checked on the 7mm Mauser 7X57. Everything seems to match up. Except the body length of the 7X57, as shown on the "Load data" pages, states the body length of the 7X57 as 1.726", and the body length of the 257R as 1.728". .002 shorter in length than the 257 Roberts, or is that perfect for a .002 bump of the 257R???

My bet is that it will work great!

Send it thru & chamber it to check. My issue was the unavailable parent case larger than 6.5mm so I’ve got to grind or buy a dedicated body die.

Let us know what you find out.

(Not a gun writer so take my suggestion with a pinch of skepticism)

Looks like I'll give it a go. This piece of writing paper is .0035", sooooooo