Huntington Reloading Specialities in CA usually has new 30 Remington brass the can be reformed (with GREAT care) to 25 rem.
Might be a good idea (next time) for buying a 6.8 spc fl die, backing it out and going from 308>277>257 in 3 steps as I lost about 20% trying one step even using Sinclair case forming lube. (shoulders collapsed) (6.8 is based on a shortened 30 rem. Too bad it's shortened or brass would be no problem !)
Qual-Cartridge also does occasional runs of 25 rem.
My perfect bore, receiver sighted M8 will hold 1.5" 5 shot groups @ 100 with generic Remington 100 gr soft points.
Fun cartridge, has more "whup azz" than the typical 6.8 short barreled carbine.