.50 Martin-Primed Identification Needed

I recently came across this cartridge marked as .50 Martin-Primed cartridge. Possibly a .50-60 or Joslyn. The cartridge on the left is the one in question. The cartridge on the right is a .50-60 Peabody.

IMG_0962

The measurements for the two cartridges is as follows:

.50-60 Peabody Rimfire
OAL 1.887"
CL 1.484"
Head D .562"
Rim D .644
CMD .506"
Rim Thickness .68"

.50 Unknown Martin-Primed: Headstamped: Raised “PAT. MAR. / 23 (dot) 1869
OAL 1.946”
CL 1.597"
Head D .562"
Rim D .660"
CMD .504"
Rim Thickness .60"

Both are fairly close in some aspects while completely different in others. I’ve slowly gone though the Philadelphia exposition book and I’m either missing it or it’s not listed?

Anyone have any clue what the designation should be?

Thanks!
Ian

1 Like

Ian, I am drawing a bank, what does “CMD” stand for?

Thanks,

Jack

Probably-
Case Mouth Diameter.

1 Like

Correct Dan. Case Mouth Diameter.

1 Like

Hi Ian, I have it classified as unknown. Here are my notes about it:

  • It is also known with a PAT 70 GRS headstamp as found in the regular .50-70 Gov’t cartridge, so one can assume it is a “.50-70” cartridge. However, since the case is too short, if the 70 grain load is correct it must have been loaded with a compressed charge. Otherwise, it was made with a shortened case.

  • There is a similar .50-70 cartridge with compressed charge (see 1876 Expo No. 235). However, it has a 39.37 mm/1.55" long case with cup anvil and 2.09" overall length.

  • It’s not a centerfire version of the .50-60 Peabody because the case is about 3 mm/0.118" longer, and is not a centerfire version of the .50-70 Peabody either, because the case is about 1.5 mm/0.059" shorter.

Regards,

Fede

1 Like

Thanks Fede! I too was looking at the FFFG powder test cartridges but I didn’t see an exact match either.