Italian Vetterli 1870/87/15 in 6.5 Carcano. Neat gun with a lot of history.
This example was manufactured in 1890, and would have been originally made as a 4-shot repeater in 10.4x47R, then upgraded later to 6.5 Carcano. This rifle is marked AOI and would have spent some time with the Italians in east Africa.
These were originally developed as a black powder single shot 10.4×47R rifle in 1870, then upgraded to a repeater with a 4-round box magazine in 1887, and finally updated to 6.5x52 (6.5 Carcano) starting in 1915.