Potential Mountain Gun case?

[Vasco Da Gama]

This little case has been in my collection for a long time, I thought to have one last chance to identify it. I don’t think it has been cut, as their appears to be a line around the inside where a closing cup may have been. Could be a blank or an impulse cartridge for something, which would explain why the base markings have been removed. Pictured next to a Schneider 70x136 case for comparison. Very happy to have your thoughts, length 110mm, mouth 74mm and rim 82.3mm

 

[Hoeksel]

Assuming 82.3 mm rim is correct, I only know 2 different lengths for a 70 mm Cart. Elec. Engine starter, post war (121 mm and 182 mm).

 

[Vasco Da Gama]

Good spot Hoeksel, and a school boy error on my part. Just had a look inside an engine starting case and the primer is the same configuration, the black coating is also present. So a cut jet engine starter, not as interesting as I hoped!