A magazine is the storage area and feeding device for ammunition in a firearm which is attached to a repeating firearm. When a gun holder fires a gun, the magazine operates by relocating the cartridges stored inside into a location that it can be fed into the chamber to create impact. A detachable magazine is often referred to as a 'clip' and are heavily monitored by gun control laws because it is an integral part of most repeating firearm.

Gun magazines are made in many shapes and sizes ranging from bolt action express rifles, that hold only a few rounds to machine guns that can hold hundreds of rounds. The guns that accept a wide variety of magazine usually use a box or drum magazine and some handguns can even feed from both magazines and belts. The most commonly used of magazine in modern firearms are the detachable box type magazines. This cartridge in this magazine is located in either the column in a staggered zig zag style or with each bullet placed one above the other. When the firearm starts to fire, then the cartridges are shifted to the top of the magazine by another follower driven by spring tension to either a side by side or a single feed position.

Certain gun magazines such as the single or multiple tubular magazine are usually found on most lever action rifles, and pump action shotguns whether round or flat nose. These magazines hold cartridges end to end inside of a spring loaded tube, running parallel to the barrel or in the buttstock and is normally fixed to the firearm when being used. The main issue with tubular magazines was that when the bullet tip made contact with the primer of the cartridge ahead of it during recoil, it would often times catch fire which made it very dangerous to use so it was made obsolete within armed forces when the pointed 'splitzer' bullets were buy gun safe online.

There are also cylindrical designed magazines such as drum and rotary magazines that let you put more bullets inside than box magazines. Drum magazines are placed mainly in light machines guns such as the Heckler & Koch MG36, but these magazines are more unreliable and complicated. In some drum magazines, the cylindrical chamber forces the loose rounds into an exit slot while the cartridge is stored parallel to the axis of rotation. When the magazine is loaded, then a wound spring forces the partition against the rounds. A single staggered column is forced by a follower through a curved path.