This is the bolt that you looked at yesterday.
It goes to the Beretta model 1918/30 carbine in 9mm Glisenti. It is a cartridge similar to the 9×19 but of much less powerful, http://en.wikipedia.org/wiki/9mm_Glisenti.
You can see the similarity to the Beretta model 38 smg bolt.
9mm Luger ammunition will fit and fire in this weapon but should not be used.
It was generally issued as a police carbine.