The 257 Ferguson is nothing more than a 7mm STW necked down to 25 caliber. It was developed years ago by Layne Simpson, a scribe for shooting magazines. He calls it the 257 STW. I believe it use' s 80+ grians of powder to push 100 grain bullets to 4000 fps. With those blazing speeds, barrel throats wont last long Simply running a 7mm STW through a 257 STW FL sizer should do the trick and then all you need is to fireform the case.


DoubleA