IMO only a handful of centerfire cartridges will get a bullet to or past 4000 fps and they usually are handloaded
It looks like a 25 cal 75 gr sierra blitz king could get to 3900 fps but doubt a 24" barrel is used. Not sure if that bullet could handle the strain, might come apart. As for making loads either learn or pay dearly for a custom load that gets close to 4000 fps..
IMO you are better off buying ammo with 100-120 gr bullets for your 257 Weatherby if you don't reload.
