The Cei-Rigotti was an Italian prototype self-loading rifle designed by Amerigo Cei-Rigotti. Notably featuring a select-fire function, the Cei-Rigotti was one of the first fully-automatic rifles in history.
Captain Amerigo Cei-Rigotti, an Italian Army officer, worked on developing gas-operated self-loading rifles in the 1890s. In 1895 he created a selective-fire prototype and demonstrated it before Victor Emmanuel III, the future King of Italy. Five years later, in 1900, Cei-Rigotti's prototype was made public in an Italian newspaper report which attracted the attention of the British Army. Trials for the weapon were arranged at RSAF Enfield in March 1901.
The Cei-Rigotti was tested by the British Army and Royal Navy in both semi-automatic and fully-automatic fire modes. However, the weapon frequently encountered stoppages and ejection issues. The action of the rifle was disliked by the testers and the accuracy was lower than desired. The build quality of the Cei-Rigotti was also criticized. After a series of tests in the early 1900s, the rifle was rejected by the British and development of it had ceased before World War I.
The Cei-Rigotti was a gas-operated self-loading rifle that utilized a short-stroke piston to move the bolt. A gas tube ran from the barrel to the receiver. The gas pressure built up inside the barrel upon firing and bled through into the gas tube via a recess located about half-way up the barrel. The pressure then traveled through the tube and pushed the piston, which operated the bolt. The internal box magazine held 25 rounds and was loaded by top-fed stripper clips, although detachable box magazines were also developed.