anyone know what this is?

[five.five-six]

30 of them got mixed in with my .308 if anyone wants it, they are in the WTG thread, all cleaned up

[JacobCR03]

I think that may be surplus 7.5mm French--normally used in the MAS-36/44/49/49-56 type rifles. I've heard that it's not reloadable, though, due to the strange primer setup, but I've never tried it.

[five.five-six]

you will bend your decapping pin, you need to use a hydraulic setup