The 7.5×55mm Swiss or 7,5mm GP 11 is a cartridge developed for the Swiss Army. It originated from the Gewehrpatrone 1890 (7.5×53.5mm) developed in 1898 by mechanical engineer Lt. Col. Eduard Rubin for rifles based on Rudolf Schmidt's action design. The 7.5×55mm Swiss GP 11 cartridge is similar in appearance to the slightly smaller 7.5×54mm French round though the two are not interchangeable.
Two 7×57 cartridges (left) next to a 7.5×55mm / GP 11 (mid), .308 Win (right) and .223 Rem (far right)
GP 90/03 ammunition
PC 88 square flake shaped propellant used in the GP 90/23 cartridge variant
Swiss Army issue 10-round GP 11 pack
The 7.5×54mm French, 7.5 French, or 7.5 MAS is a rimless bottlenecked rifle cartridge. It was developed by France as an update to the 7.5×57mm MAS mod. 1924 cartridge. It replaced the obsolete 8×50mmR Lebel round used during World War I, and served as the French service cartridge until superseded by the 5.56×45mm NATO and 7.62×51mm NATO cartridges in the 1970s and 1980s.
Belted 7.5×54mm French ammunition for use in the MAC 52 aircraft variant of the AA-52 machine gun.