Unless my searching skills are poor, I can't find a list of resized/fireformed calibers.
I think it would be a great resource for some folks. Let's start it:
I'll even list the obvious because one never knows the jam they can get into.
I'll do the easy ones and as the list grows, I'll try to keep up on it (keep it all here in the first post)
.38 special from .357 mag
.44 special from .44 mag
6.5 grendel from 7.62x39
8mm mauser from .30-06
.308 from .30-06
6.5 x55mm Swe. Mauser from .30-06
7.65 x 53mm Arg. Mauser from .30-06
9.5x57 Mannlicher-Schoenauer brass from 30-06 or .35 Whelen
41 Long Colt cases from .38 Special cases
300 RUM from 404 Jeffery or 7mm RUM
7mm RUM from 404 Jeffery or 300 RUM
223 sized to 7mmTCU
250/3000 (250 Savage) from 22/250
7.5x55 Schmidt-Rubin from .284 Win.
7mm Intn'l (IHMSA) from .300 Savage
7 BR Rem. from .308 WCF (a real PITA but doable)
6.5 JAP from 35 Remington (sized with a 308 Win die first to limit the neck collapses)
6.5 Jap from 220 Swift - run it through a trim die first to knock it down to the proper 50mm length and then just resize.
7.62x25 Tok from 223 Rem cases. cut down to 25mm and then reform.
9mm Largo cases from 38 Super cases. Chuck the 38 super cases into a drill chuck and file the semi-rim down first and then size them in case you've crumpled the necks with the drill chuck.
7-30 Waters from .30-30.
ALL the 'x57s', up or down, 6mm Rem., .257 Roberts, 7x57, 8x57.
(Parent case design is 7x57.)
.22-250 from .250 Savage, like when it was a wildacat and no factory ammo was available.
.303 British to all the Epps cartridges and the NZ inventions like the Pygmy.
.220 Swift from .30-06.
.300 Whisper from .221 Fireball.
Keep it going