1.(Gun.) Firing shots in rapid succession.
2.(Ordnance) Capable of being fired rapidly; applied to single-barreled guns of greater caliber than small arms, mounted so as to be quickly trained and elevated, with a quick-acting breech mechanism operated by a single motion of a crank or lever (abbr. R. F.); specif.: (1) In the United States navy, designating such a gun using fixed ammunition or metallic cartridge cases; distinguished from breech-loading (abbr. B. L.), applied to all guns loading with the charge in bags, and formerly from quick-fire. Rapid-fire guns in the navy also sometimes include automatic or semiautomatic rapid-fire guns; the former being automatic guns of not less than one inch caliber, firing a shell of not less than one pound weight, the explosion of each cartridge operating the mechanism for ejecting the empty shell, loading, and firing the next shot, the latter being guns that require one operation of the hand at each discharge, to load the gun. (2) In the United States army, designating such a gun, whether using fixed or separate ammunition, designed chiefly for use in coast batteries against torpedo vessels and the lightly armored batteries or other war vessels and for the protection of defensive mine fields; not distinguished from quick-fire. (3) In Great Britain and Europe used, rarely, as synonymous with quick-fire.
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