8ÃÂ59mmRb Breda was an Italian heavy arms cartridge. It is unusual in that it is one of the small number of cartridges designed with a rebated rim, meaning the rim of the cartridge is smaller in diameter than the body of the cartridge. The "Rb" in the designation stands for "rebated rim".
8ÃÂ59mmRB Breda was a caliber created for use by the Royal Italian Army in World War II. The cartridge was originally designed for use in anti-aircraft heavy machine guns like the Breda M37, Breda M38, and FiatâÂÂRevelli Modello 1935. It was also used in the experimental Pavesi M42 semi-automatic rifle. It was introduced in 1935 but is no longer in production today.