Headstamp n primer marking help please

[spotter]

Hello everyone
Ive just cleaned a trench arted cartridge (Engraved with chinese style dragons) for a neighbour and wondered if someone could id the stamps on the cartridge base please
The mouth of the cartridge measures approx 75mm
The primer is marked 13 - 10 is this the dates 1913 or 1910 ????
The base has a small stamp of GC

Thanks for looking
Allan

 

[Alpini]

Looks like a 75x278R, made by the Grammophone Company for Belgium.

 

[Big Dave]

Beaten by Alpini ,but was going to say the primer looks Belgian

 

[Hoeksel]

And I would go for Belgium as well ;-).

 

[spotter]

Thanks to all for the replies and id