.236 U.S.N and 6 mm U.S.N

First cartridge head stamp .236 U.S.N .

Second cartridge headstamp 6 M/M U.S.N.

The bullet diameter was measured just in front of case mouth on both un cleaned rounds .

.236 U.S.N .2433 steel jacket magnetic

6 mm U.S.N. .2445 copper jacket

The .236 weighs 350.54 grains .
The 6 M/M weighs 294.20 grains .

Is the .236 from the May 1895 Bureau of Ordnance test ?

The W.R.A.co 6M/M U.S.A. Is this a 24NF primer ?
The soft point bullet has a copper jacket which is after 1928 I believe.

Any more information on these rounds will be appreciated .
Doing a search I find a lot of wrong information .


Is this the .236 USN with 135gr bullet?

I didn’t know they ever made a rimmed version…

Your rimmed case has the 6mm shoulder, a legitimate variation.
The rimmed and rimless cartridges are found with both the longer 236 shoulder, and the shorter, sharper 6mm shoulder. So 4 main case /headstamp variations.