Help IDing old cartridge

[Kaitum]

I found this casing on the ground over the weekend. I'm curious what cartridge it may have been a part of. It's 1.775" long by 0.57" outside diameter (of the still rounded end) with a wall thickness of 0.025". So just over .50 caliber give or take. No head stamp is visible. The area had a military presence during the late 1800s. Not sure if it's that old but it's certainly from awhile back.

 

[FairWeather]

No idea. My first thought was 20ga, but that would be a very short shell.

 

[p_ham]

What's the rim diameter and the body diameter just ahead of the rim?

My first though because of the Benet style primer is 50-70.

 

[Kaitum]

Rim diameter is 0.66" and body diameter just in front of the rim is 0.57". I misread my calipers initially. Damn aging eyes....

 

[Kaitum]

My first though because of the Benet style primer is 50-70.

The pictures of a 50-70 government certainly looks like it. Thanks!

 

[Sheltowee]

It would appear that you got a gen-u-wine .50-70 Government case. Cool find!