This rifle is in the configuration of the M91/28TS although the markings on the barrel would not be correct for this model were it new built in 1928. However, several thousand M91TS were upgraded to M91/28TS with the addition of a new handguard, nosecap and bayonet lug. I suspect your rifle with the 1917 date is one of the latter. These are the first rifles Mussolini had manufactured after the fascists took over in 1922. Neat, historical rifle. Best. Tom