Even seasoned collectors of US Military often get confused when trying to ID and catalog the pre-NATO Cal .30 Light Rifle cartridges. Here’s a quick guide that may help. Be aware that this is very basic and does not account for all the twists and turns in the development of this cartridge.
First, it’s necessary to separate the case from the cartridge. Each case had it’s own official designation and many collectors tend to mix case designations with cartridge designations, leading to all sorts of identifications that are not official and confusing at best.
300 SAVAGE - Commercial case first used to determine the basic feasibility of the project goals. Headstamps most often encountered are SUPER-X, SUPER SPEED, and REM-UMC.
T65 - The first Frankford Arsenal case, nearly identical to the 300 Savage,1.87" long. Headstamps are FA 45, FA 46, and FA 47.
FAT1 - 1.95" case, thin rim, wide extractor groove. Headstamps are FA 47, FA 48, and FA *48.
FAT1E1 - 1.95" case, thick rim, narrow extractor groove. Headstamps are FA*48, FA 48, FA 49, and FA 50.
FAT1E2 - 1.95" case. None known to exist.
FAT1E3 - 2.01" case. The final design. Headstamps are FA 49, FA 50, FA ●50● , FA 51, FA 52, FA 53, FA 54, LC 54, and WCC 54.
Next, I’ll get into the different cartridges.
If anyone sees any errors or ommissions, PLEASE let me know.