A cylinder breech block device (100) of a repeating firearm has a breech block cylinder (200) pivoted in a system housing (160) of the repeating firearm for execution of repetitive action thereof and capable of being locked to said system housing (160) for firing a round. A firing pin (140) capable of being cocked by a tension spring is mounted for linear displacement in the direction of a cartridge (141) stored in a magazine (141) of a barrel (143). Cocking of the firing pin (140) is effected by causing rotation, through a predefined angle, of a breech bolt handle (300) rigidly connected to a tension crown ring (400) that is pivoted on a central shaft (210) of the breech block cylinder (200).