When it comes to magazine, many people are no strangers. A rigid flat box, either straight or curved, with a spring loaded plate inside. "This style, to be honest, is difficult to associate with the word 'lively'.". But when it comes to the location of the magazine design, it immediately hooks up with "liveliness", either left or right, or up or down, with different situations. Recently, Germany's Hera Weapons Company and Austria's Weir Precision Engineering Company jointly launched a bolt operated rifle, the HERA H6. Unlike most rifles, the magazine of the gun is mounted on the left side of the magazine. This unique setting can't help but remind people of the Ston submachine gun used during World War II. Of course, this change in the position of the magazine is not only reflected in rifles and submachine guns. If you focus on more gun types and "quickly replay" relevant historical clips, the changes in the magazine relative to the gun body can be described as "jumping around.". In World War I, the magazine was usually located at the bottom of a semi-automatic rifle. For example, the Mauser M1916 semi-automatic carbine gun used by the German Air Force uses this setting. This magazine setting later developed into the mainstream of most rifles and submachine guns today. Of course, there are "usually" and "exceptions". At that time, the MP18 submachine gun designed by German ordnance designer Schmeiser appeared somewhat "alternative". Considering the requirements of trench warfare, the MP18 adopts a left loaded magazine design to reduce the aiming baseline and the exposure area of soldiers during firing. It uses a double row straight magazine for ammunition supply, and later added the method of using a snail shaped cartridge drum for ammunition supply. Unlike the left cartridge of the MP18 submachine gun, the LMG25 light machine gun designed in the 1920s by the Swiss Bern Military Industry Factory uses a right cartridge. The LMG25 light machine gun was later installed in the Swiss army and served until the 1950s. During World War II, the density of firepower on the battlefield increased significantly, and ground operations placed greater emphasis on mobility and suppression. The Owen submachine gun, which was fed from the top of the gun body, emerged as the times require. This magazine setting method is also conducive to prone shooting and rapid replacement of magazines. Moreover, under the action of gravity, bullets can be easily fed into the casing, and after firing, the cartridge case will also be thrown downward using its own weight, improving the efficiency of throwing the case. Of course, the Owen submachine gun is not the "first person" to feed ammunition on the top. The Czech ZB-26 light machine gun, introduced in 1926, also features a top ammunition supply design, but uses a curved magazine. These creative designs under specific circumstances played their due role at that time. However, in the long run, side and top mounted magazines also have certain shortcomings. Side-mounted magazines can make the portability of firearms worse, shift the center of gravity of the entire gun, increase the difficulty of handling, and affect the trajectory of continuous firing. The top mounted magazine would block the aiming baseline of the sight, forcing the gun's sight and shutter to be set "elsewhere.". Therefore, the vast majority of rifles and submachine guns at that time still adopted the traditional lower cartridge design. However, even if the magazine is placed underneath, there are also those who "escape sideways and slant out". To make submachine guns more portable, the Czech Republic's Brno Arsenal introduced the ZB-47 submachine gun after World War II. This gun has a maximum