tubular magazine firearm by topping off the magazine by loading new rounds to replace the rounds that have just been fired. This is especially important when hunting, as many locations have legal limits on the magazine capacity: for example, three rounds for shotguns and five rounds for rifles. The BSA Machine Carbine used a unique pump-action that also required twisting the handguard. Another variant was the Burgess Folding Shotgun from the late 19th century where instead of manipulating the forend to cycle the action, it had a sleeve around the grip area of the stock which the shooter would slide back and forward to cycle the gun. This was done because the forend based pump action was under patent at the time. Shotguns Pump-action shotguns, also called pump shotguns, slide-action repeating shotguns or slide-action shotguns are the most commonly seen pump-action firearms. These shotguns typically use a tubular magazine underneath the gun barrel to hold the shells, though there are some variants that use a box magazine like most rifles. It's not uncommon to see extra ammunition stored in externally mounted "shell holder" racks (usually as "sidesaddle" on one side of the receiver, or on the buttstock) for quick on-field reloading. The shells are chambered and extracted by pulling/pushing the sliding fore-end enveloping the tubular magazine toward the user. In modern shotguns, the fore-end can be replaceable and often include picatinny rails or M-LOK for mounting accessories such as a tactical light, and the traditional straight grip might be replaced with a pistol grip for a more stable control. Trigger disconnectors Modern pump shotgun designs, such as the Remington 870 and Mossberg 500, have a safety feature called a trigger disconnector, which disconnects the trigger from the sear as the bolt moves back, so that the trigger must be released and pulled again to fire the shotgun after it closes. Many early pump shotguns, such as the Winchester 1897, did not have trigger disconnectors, and would, if the trigger were held back, fire immediately upon closing. Due to the higher rate of fire that this allows, some shooters prefer models without this feature, such as the Ithaca 37, Stevens Model 520/620, and Winchester Model 12. Rifles When used in rifles, this action is also commonly called a slide action or more commonly referred to in the 19th century as a trombone action. Colt manufactured the Colt Lightning Carbine from 1884