Those appear to be Herters. I have 3 sets .243, 6.5x55, and .270 and the .270 set doesn't have a manufacturer stamped on it. The .243 and 6.5x55 set have fancier lock rings that are marked Herters. Hope this helps.
Earlier Lachmiller or something like that with later RCBS lock rings. Haven't a clue on the box.
Facta non verba
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 |