A semi or full-automatic firearm which is said to fire from a closed bolt is one where, when ready to fire, a round is in the chamber and the bolt and working parts are forward. When the trigger is pulled the firing pin or striker fires the round, the action is cycled by the energy of the shot sending the bolt to the rear which extracts and ejects the empty cartridge case, the bolt then goes forward feeding a fresh round from the magazine into the chamber, ready for the next shot.
When World War I era machine guns were being tried for use on aircraft, the Lewis gun was found not to be usable with a gun synchronizer for forward firing through the propeller, due to its firing cycle starting with an open bolt. The Maxim style arms used by both the Allies, as the Vickers machine gun and Central Powers, as both the LMG 08 and LMG 08/15 Spandau gun, and Parabellum LMG 14 gun, all fired with a cycle starting with a closed bolt, and since the bullet firing from the gun started the firing cycle, it was much easier to set the synchronizer to only trigger the gun when the propeller's blade was not in front of the gun.
Read more about Closed Bolt: Closed-bolt Firearms, Mixed Mode Firearms
Famous quotes containing the words closed and/or bolt:
“No other creative field is as closed to those who are not white and male as is the visual arts. After I decided to be an artist, the first thing that I had to believe was that I, a black woman, could penetrate the art scene, and that, further, I could do so without sacrificing one iota of my blackness or my femaleness or my humanity.”
—Faith Ringgold (b. 1934)
“There are two kinds of men, and only two, and that young man is one kind. He is high-minded, he is pure, he’s the kind of man that the world pretends to look up to, and in fact despises. He is
the kind of man who breeds unhappiness, particularly in women.”
—Robert Bolt (1924–1995)