Is this carbine ammo?

[TennBill2]

I was digging through my surplus metal ammo cans looking for some ammo and came upon this box. I've had it for probably 20 or 25 years. Bought a bunch of 30 cal ammo for my Luger pistol at various gun shows. I had tried some regular old 30 ammo in my carbine and it would not cycle. Can anyone identify what this is? Bill