Does anyone know what they call a 25cal. built on the 264 win mag case? I know it would be almost identical to the 257 weatherby, but with out the high price brass. I already have a good supply of 264 brass and just thought about a hot 25cal on this, just don't know what to call it when tring to find someone with a reamer. Thanks

257 Baker Magnum just necked down, or with a 45 degree shoulder and straightened body, a 25 ICL Magnum.

the 25x300wsm or 257JLS, is a perfect twin of the 257wby, with cheap brass. THough making it from 270 WSM is easier.

jeffe

I'd just do a 257 Wby and neck down 7 RM brass to keep the brass a bit cheaper.

I did it for years with a 270 Wby so see no reason why it wouldn't work with a 257.

Mark D

.25 Arnold (Arnold Arms promoted this cartridge). I would also have a .257 Weatherby design because it has a longer neck which the Smalley-McPhearson team says leads to longer barrel life. You could use off the shelf Forester or Redding dies. If I was going to the expense of a custom reamer, I would load up some of the bullets you plan to use, seated to the bullets out to where the magazine would allow and send that combination to the reamer maker. Weatherby SAMI Spec dies will have a 5/8 leade before the lands. I would encourage a more normal and potentially accurate chamber with only enough lead to seat the bullets in a hot barre.

Like Mark just said. My 257 Wby has never seen a Wby case. All I've ever used is 264 Win cases run through a 257 die. 7mm Rem cases will work but you may want to watch for thick necks. The only thing I would advise you watch for is case capacity. The Wby cases have more volume and a max load in a wby case will be excessive in a Win or Rem case. Reduce loads for Wby cases about 3 grs for Win cases.