The 6.5×53mmR, originally and more correctly produced as the 6.5×53.5mmR, and in imperial system nomenclature known as the .256 Mannlicher, is a late 19th-century rimmed centerfire military rifle cartridge similar to other early smokeless powder designs.
French copy of an original cartridge drawing
French copy of an original cartridge detail drawing
French copy of an original chamber drawing
Romanian Mannlicher M1893
The 6.5×52mm Carcano, also known as the 6.5×52mm Parravicini–Carcano or 6.5×52mm Mannlicher–Carcano, is an Italian military 6.5 mm rimless bottle-necked rifle cartridge, developed from 1889 to 1891 and used in the Carcano 1891 rifle and many of its successors. A common synonym in American gun literature is "6.5mm Italian." In American parlance, "Carcano" is frequently added to better distinguish it from the rimmed hunting cartridge 6.5×52mmR. Ballistically, its performance is very similar to that of the 6.5×54mm Mannlicher–Schönauer.
A 6.5×52mm Mannlicher-Carcano formerly owned by Lee Harvey Oswald from Warren Commission as part of its investigation of John F. Kennedy's assassination
(Left to right) 8mm Mauser (also called 7.92mm Mauser), 6.5mm Carcano, and 7.35mm Carcano
A 6.5×52mm Carcano cartridge loaded with a modern hunting bullet
A six-round en-bloc clip