You can find a powder that will "work" in all of the calibers listed but it will not "work the best." You will find that guns in the same caliber might require different powders in each to work the best. Guns are like women, no two alike, thank goodness.
I use imr 4227 quite a bit for 308 and 7.62x39
its a very interesting article(http://castboolits.gunloads.com/show...s-vs-Alliant-B).
I feel like I must be missing something here. The obvious answer to the OP is Trail Boss. Fill 'er up and you're good to go---no load data needed, and one powder works for all.
I have not found a powder better than Reloader #7 for cast bullet loads for 30-30 Win, 308 Win, and 30-06 Springfield.
DRB #2276 President's Hundred 2021
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |