“Special Troops” does not mean Special Forces; it means all the various service branches that need neither a full length rifle nor a permanently attached bayonet. This included artillery, engineers, naval troops, and more. The Moschetto 91 TS was basically a carbine-length Carcano rifle, albeit with a unique perpendicular bayonet lug. These carbines became quite popular during World War One. After the war, instead of restarting M91 TS production, the Italian military opted to convert worn out M91 long rifles to TS carbine pattern. This model is easily identified by the short barrel but long rear sight base, and was designated the M91/24. More than a quarter million of these conversion were made at the Terni Arsenal between 1924 and 1929.
When the supply of suitable candidates for long rifle conversion ran dry, production of the M91 TS restarted, now using standard bayonet lugs. They would remain in production until 1938, when Italy adopted the 7.35mm cartridge, and after the reversion to 6.5mm in 1940. They are extremely handy little carbines!
Thanks to InterOrdnance / Royal Tiger Imports for providing these carbines from their Ethiopian imports for the video!