the American C-More Competition M26, as well as the indigenous-designed SHS STP 12, have become increasingly popular alternatives to lever-action shotguns, largely due to the better ergonomics with less stress on the shooter's trigger hand and fingers when cycling the action. Revolver Colt briefly manufactured several revolving shotguns that were met with mixed success. The Colt Model 1839 Shotgun was manufactured between 1839 and 1841. Later, the Colt Model 1855 Shotgun, based on the Model 1855 revolving rifle, was manufactured between 1860 and 1863. Because of their low production numbers and age they are among the rarest of all Colt firearms. The Armsel Striker was a modern take on the revolving shotgun that held 10 rounds of 12-gauge ammunition in its cylinder. It was copied by Cobray as the Streetsweeper. Taurus manufactures a carbine variant of the Taurus Judge revolver along with its Australian partner company, Rossi known as the Taurus/Rossi Circuit Judge. It comes in the original combination chambering of .410 bore and .45 Long Colt, as well as the .44 Remington Magnum chambering. The rifle has small blast shields attached to the cylinder to protect the shooter from hot gases escaping between the cylinder and barrel. The MTs255 () is a shotgun fed by a 5-round internal revolving cylinder. It is produced by the TsKIB SOO, Central Design and Research Bureau of Sporting and Hunting Arms. They are available in 12, 20, 28 and 32 gauges, and .410 bore. Semi-automatic Recoil/inertia-driven or gas-operated actions are other popular methods of increasing the rate of fire of a shotgun; these self-loading shotguns are generally referred to as autoloaders. Instead of having the action manually operated by a pump or lever, the action automatically cycles each time the shotgun is fired, ejecting the spent shell and reloading a fresh one into the chamber. The first successful semi-automatic shotgun was John Browning's Auto-5, first produced by Fabrique Nationale beginning in 1902. Other well-known examples include the Remington 1100, Benelli M1, and Saiga-12. Some, such as the Franchi SPAS-12 and Benelli M3, are capable of switching between semi-automatic and pump action. These are popular for two reasons; first, some jurisdictions forbid the use of semi-automatic actions for hunting, and second, lower-powered rounds, like "reduced-recoil" buckshot shells and many less-lethal cartridges, have insufficient power to reliably cycle a semi-automatic shotgun. Automatic Fully automatic shotguns, such as the 1960's (appeared in 1967) Vietnam War era