These two came out of the same gun, kind of a small Belgian bulldogtype pocketrevolver in .380 And yes: surprise!
Sure a surprise to be discovered when the owner was going to shoot it. Besides the 100 year old ammo…
In short, likely none of both would have functioned.
Are we sure that the one on the left is not inside-primed center-fire? I don’t know enough about this caliber to know for sure, but for example, the 7.65 mm Pickert by GFL looks like a rim-fire, and it is center-fire. Just curious.
According my Cartridge Headstamp Guide (first revision) the Gévelot is indeed an inside-primed centre-fire. So: bang-bang! (100 years ago…)
For info, here’s a Gaupillaut .380 Inside Primed cartridge that I sectioned, same headstamp as your example, to see what it looks like inside. Ironically it’s quite common to find these with a number of firing pin strike marks around the rim because people have assumed they are rimfire cartridges.