POTD: Italian Thumper – Tromboncino M28 Grenade Launcher
Sam.S 05.16.24
Welcome to today’s Photo of the Day! In the late 1920s, the Italian military sought to provide infantry with an organic grenade-launching capability. Their unconventional solution was the Tromboncino M28 – a grenade launcher integrated into the Carcano M91TS carbine. The Tromboncino utilized a unique “shared bolt” design. The carbine’s bolt could be removed and inserted into a separate receiver mounted on the rifle’s right side. This second receiver terminated in a grenade launching cup instead of a barrel. Rather than employ blanks, the Tromboncino launched standard 6.5x52mm Carcano rifle ammunition to propel its grenades. A bullet trap at the muzzle allowed fired bullets to obturate gases, venting them out rear ports to launch the 38.5mm projectile from the cup. While ingenious in conception, the Tromboncino suffered from anemic grenade performance. Designed as an offensive weapon for shock assaults, its low-explosive grenades lacked sufficient fragmentation effects for combat use. After just 6 years of service, the complicated and expensive Tromboncino was declared obsolete in 1934. It was replaced by conventional mortars like the Brixia Model 35 for infantry fire support. Though innovative, the Tromboncino’s flawed grenade ammunition doomed this ahead-of-its-time weapon system.
“Developed in the late 1920, the Tromboncino M28 works on the same mechanical principles as a typical “cup” launcher (a discharged cartridge supplies propellant gas to a projectile resting in a chamber), but with a twist; instead of simply attaching a grenade chamber to the muzzle of a rifle, the M28 uses a dedicated blank-only receiver with mounted grenade chamber, which is then affixed to the right side of a complete infantry rifle. This combination was only in use from about 1928 to 1934, where it was retired in favor of a dedicated light infantry mortar; most were scrapped with the base firearms returned to standard configuration. The trigger mechanism is interconnected to both the rifle and the launcher, and in order to save weight and prevent inadvertent discharge both share a single bolt. “
Lot 1618: Gardone V.T. 91/38TS Carcano, “Tromboncino M28” Grenade Launcher – Gardone Val Trompia Carcano Model 91/38TS Bolt Action Rifle with Rare ‘Tromboncino M28’ Grenade Launcher. (n.d.-s). Rock Island Auction Company. photograph. Retrieved May 15, 2024, from https://www.rockislandauction.com/detail/73/1618/gardone-vt-9138ts-carcano-tromboncino-m28-grenade-launcher.
