Friend has this old round. Base says SMI and possibly 936, pretty bad shape. The bullet mics at .266 and is 1.25 long, the case is just a tad over 2.1. You can see the powder is round like a tube with a hole thru it. Cordite maybe?
Really good guess, it is 6.5mm Carcano. SMI stands for Societa Metalurgica Italiana and 936 is the date code (September of 1936). The Italian tube powder is selenite, not cordite.
