breechblock


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breechblock

[′brēch‚bläk]
(ordnance)
A movable steel block in the mechanism of a breech-loading gun that seals the breech opening of the barrel during firing.
References in periodicals archive ?
This breechblock was in the original Model 51 and is referred to by most people as the Pedersen block, and it has been tweaked to handle 9mm +P.
Starr's carbine was first tested by the military in the latter part of 1858 when it was found to perform "remarkably well" and felt by some to be superior to the Sharps in that its flat-based cartridge did not require being cut by the breechblock, as did some of the Sharps ammunition.
Select a drill a few thousandths larger than the diameter of the firing pin body (the large diameter) and drill a hole from the rear of the breechblock to a depth that will just intersect with the smaller diameter hole.
That lets the breechblock close firmly, but the constant pressure wears out the springs and leads to early failure.
The hammers of the first Winchester Single Shots came to fullcock when the breechblock was raised, and Winchester advertised this as an advantage over the Ballard and Remington Hepburn rifles, which had to be manually cocked after raising the breechblock.
After the war, Remington's engineers redesigned the action so the rotating breechblock was locked in place by an extension of the external hammer as it fell.
Worn breech assembly components can cause the firing pin to protrude past the face of the breechblock.
Originally the slide was made from a steel stamping, folded and welded into shape, with a hardened steel breechblock inserted.
The breechblock holds the spring-loaded firing pin, the extractor and a spring-loaded loaded-chamber indicator that protrudes through a hole drilled into the rear end of the slide.
Venturing out to the range, I practiced firing at targets set at 50 and 100 yards while holding two additional shells between the fingers of my supporting hand, flipping open the breech and immediately plucking one of the shells from my fingers, chambering it and snapping the breechblock closed, ready for a second shot.
It is not connected to the breechblock carrier like that of the Kalashnikov.
The system incorporates a device to guard against hang-fire; the breechblock senses the hang-fire and clears the jam within two seconds.