50-70 Cartridges Primer Type?


This is probably an ignorant question, but I was wondering how to describe the primer for these cartridges. I know generally they are probably referred to as “inside primed”, but can they be identified further such as “Benet Primed” or “Benet Primed, steel anvil”. I would appreciate any advice or information.

From left to right a 50-70, another 50-70, then a 50-55-430 Carbine.



They are all Benet primed. The higher grooves on the one in the middle indicate it has the iron anvil, which should attract a magnet; the lower grooves indicate the other two have the shorter copper anvil. Are you certain about the identification of the one on the right? I have a similar one, and have wondered about that odd bullet.

According to Murphy in The Ordnance Department at the 1876 Philadelphia Exposition. The Navy experemented with Benet primed 50-70 with 385 grain bulets. Cartridge on the right might be one of these.


Thank you Guy for the information. I never knew those particular facts before nor have I found such information in any of my meager references. I learned something today.

As for the identification of the 50-55-430 cartridge, this cartridge came with a label identifying it as such. I have seen many incorrect labels on specimens before, most notably some explosive rounds which were misidentified as tracers, and this round could be misidentified too. If someone knows or has a better identification such as Gourd’s, I am open to that. In fact, I think Gourd’s identification seems probable.

I did try the magnet test and it was attracted to the cartridge with the higher grooves, or the steel anvil. The other two didn’t attract the magnet.


These oddball cartridges sure do make this hobby challenging. I had thought it might be what Hoyem refers to in Vol 3 of his History & Development of Small Arms Ammunition as a Roberts bullet, but it doesn’t appear quite blunt enough.

The following may help you to pin down the years of manufacture of the Benet primed 50-70 cartridges. (WITH OUT HEADSTAMPS )
Oct. 1866 to Mar. 1868
iron bar anvil-LOW INDENTS

Mar.1868 to Aug. 1870
Benet iron cup
indents .255 from base

Aug. 1870 to Nov. 1871
Benet copper cup
indents .255 from base

Nov. to Dec. 1871
Martin primed with re-entrant fold (not Benet )

Dec.1871 to Jan. 1872
Benet copper cup
indents .197 from base
no headstamp

Hope this helps with the dates. M. D. Rea

I vote for the cartridge at right being the .50-55-430. The low primer crimp and slight case neck are consistent with the period of production given by Lewis (Jan. 1872-Aug. 1873), and the bullet form, which suggests the 405 gr. .45-70, is typical of the .50-55-430. The latter is pictured in Lewis’ presentation of the Philadelphia centennial display. JG