81mm Mortar Igntion cartridges with box

Here are some old shotgun rounds I got from the father of one of my friends. They came in this box:

The box contained two blue and two black rounds, here are the picture:

The headstamp is: 81mm CARTOUCHEAIE FRANCHAISE

Does anyone know anything about theese?

Propellent cartridges for 81 mm mortar

81 M/M F.A.Mle 1932 = Obus de mortier de 81 mm en Fonte Aci

Thank you so much for your reply.

I’ve been lurking around this forum for a long time, and I was hoping from an answer from you.

Is this ammunition rare?

This ammunition is not rare in France.

Thank you so much for your answer.

I will certanly keep this ammunition anyway, it’s very interesting.