Unknown .308?

So today i was at a fair and i found this thing, my guess is its some sort of short range ammunition but im not certain.
Full length 66mm
casing 54mm
bullet width around 7.9mm
Non magnetic casing, very light.
Plastic projectile.
No markings.20180505_20590820180505_205936

French 7,5x54 Tir Réduit Mle F1. Aluminum case, orange plastic projectile with a copper ring at the base.