Your rifle is likely chambered in 6.5x52 Carcano. This can be veried by a gunsmith.
how much is the carcano rifle worth
6.5 Carcano was one.
You MAY be describing a Carcano military rifle. If so, values about $150, depending on condition.
A 6.5 x 52 mm Italian Carcano M91/38 bolt-action rifle.
The Mannlicher-Carcano has a six round internal magazine.
A surplus 6.5 mm Carcano rifle.
the rifle, a mannlicher-carcano rifle, is in the US national archives.
carcano rifle
A Carcano rifle.
Six rounds.
50-250 USD or so