The .45 S&W/Schofield Government cartridges that I have headstamped F 4 87 are dimensioned as follows:

Rim dia. .522 w/o bevel for semi-auto pistol extraction
rim thickness .055
case dia. .470
case length 1.102
Overall length 1.417
Lead bullet dia. .450-2

Quite different from the FA 4 06 round described above.

This is the final configuration of this Frankford round. It has the latest improvements with the crimped-in internal Benet primer of the original 1875 Schof/Frankford round replaced with a standard Boxer external primer.

If Frankford was experimenting with a combination cartridge for both revolver and pistol (which I doubt), the rimmed FA 4 06 may have been the 'experimental' round in question. Both revolvers and semi-auto pistols were included in the 1907 trials. But the 45 S&W/Schofield Government cartridge was only suitable for revolver, it would not have been suitable for semi-auto pistol also still in an early experimental stage and the main reason for the need of a new cartridge. The 45 S&W/Schofield Government was a long time produced round already in inventory at the time and therefore not an 'experimental' round nor would there be a need to specially produce 10,000 rounds of it.

A 45 Special chambered TL chamber dimension would be extremely helpful.

__________________
Jim
S&WCA #819