.22 CB

The .22 CB Cap — “Conical Bullet” — is a quieter, slightly more powerful development of the .22 BB Cap that Louis-Nicolas Flobert had invented decades earlier, first catalogued in 1888. It shares the BB Cap’s tiny 6.86 mm case, barely a third the length of a .22 Long Rifle’s, and both are known in Europe under the single name “6mm Flobert.” The case holds essentially no propellant of its own: the primer alone drives the bullet, which is what keeps muzzle report down to almost nothing from a longer barrel.

That quietness came at the cost of everything else. Contemporary reference works describe the CB Cap as combining most of the disadvantages of the BB Cap and the .22 Short into one round: no more accurate than either, louder than the BB Cap it was meant to improve on, and penetrating deeply enough to need the same backstop as a full-power .22 Short, which erased the point of using it indoors. American makers dropped it by the 1940s. It has stayed in production in Europe for low-powered pest-control rifles, and modern manufacturers also sell “.22 CB Short” and “.22 CB Long” rounds that reuse the standard .22 Short and .22 Long cases loaded down to the original CB Cap’s near-silent report — a different case from the one this entry describes, built to feed through ordinary .22 rimfire actions rather than the dedicated Flobert-pattern guns the original cartridge required.

Case and bullet dimensions here are transcribed from the current C.I.P. datasheet for the small original case and are verified. No C.I.P. maximum pressure is listed for this cartridge, and no manufacturer states a barrel length alongside a muzzle velocity for it, so this entry records only the bullet mass of two published loads, each estimated from a secondary reference (Cartridges of the World) rather than a primary source. The photograph shows the small original CB Cap beside a .22 Short and a .22 Long Rifle for scale, not the modern standard-case “.22 CB Short.”