to 1904 chambered in .44-40 caliber. The slide action Winchester Model 1890 chambered in .22 caliber was one of the most successful repeating rimfire rifle made by Winchester. Approximately 849,000 Model 1890 rifles were produced between 1890 and 1932. Later pump-action rifles were also manufactured by Winchester, Marlin, Browning and Remington. A "reverse pump-action" design can sometimes be found, where the extraction is done by pushing the fore-end forwards, and re-chambered by pulling backwards. One such 21st-century variant is the Krieghoff Semprio "in-line repeating rifle". The Semprio is a reverse pump-action system that ejects cartridges when the fore-end is pushed forward and loads the chamber when pulled backward. The Semprio's 7-lug bolt head design displays a locking surface of compared to the of the Mauser M98 bolt-action rifle. Airguns The term pump-action can also be applied to various airsoft guns and air guns, which use a similar mechanism to both load a pellet and compress a spring piston for power, or pneumatic guns where a pump is used to compress the air used for power. See the airgun article for information on how spring piston and pneumatic airguns work. Grenade launchers The 43mm GM-94 is a pump-action grenade launcher developed by the KBP design bureau for use by Russian special forces. It carries three rounds in an above-the-barrel tubular magazine. Another pump-action grenade launcher is the China Lake grenade launcher, which saw usage by the U.S. Navy SEALS in the Vietnam War in limited numbers. See also List of pump-action rifles Other long gun actions Single-shot Break-action Rolling block Falling block Repeating Revolving Bolt-action Lever-action Self-loading (semi-/fully automatic, select fire) Recoil operation Blowback Blow-forward Gas operation References Firearm actions Pump-action shotguns