Help ID Oddball

I’ve had this for at least 20 years with no idea what it is. Any ideas?
Bullet diameter: 7.39mm
Neck diameter: 7.84mm
Shoulder diameter: 11.87mm
Head diameter: 11.86mm
Rim diameter: 12.19mm
Case length: 82.02mm
O/A length: 106.69mm.
“Bullet” has an exposed steel tip and looks like the remains of tinning. It also looks roughly turned. The “Case” is brass, with a copper “Primer”.


Is it a Peterlongo? Viennese Gunmaker??? Known for very long 70mm plus cases
Doc AV.

I don’t know, I couldn’t find anything really close to it.
I did forget to mention that it is a solid piece, like something that an engineer might use during design and construction.
I got it because I thought it might be something for a 1920s-30s anti-tank rifle.

There is a cartridge in Ian V Hogg`s book called .30 US Experimental ( c 1912 ) that matches in every measurement except the projectile which is shown as .311 ( 7.93mm ) maybe a variation of that?

Do you mean the .30 Schuler (1921)?

No,it`s named as I copied it from his book…Pete.

Which book? OK, I found it. Pg 29 “The Cartridge Guide”.
Under Necked, Rimless:
Rim .470
Case 3.350
Body .465
Neck .352
Bullet .311
Jon’s looks more necked than HWS I pg 278, but?

Could be, considering the use/damage mine shows. If I recall, I got it from either Bill Dibbern or John Hintlian, two guys who had dug up lots of old Connecticut River Valley arms factory artifacts; Colt, Marlin, Henry, Winchester, Smith & Wesson, etc.

I will probably have it at SLICS, if someone wants to see it, or needs to take it home more than I need to keep it.