MERRILL GUN.
This breech-loading rifle has a fixed chamber closed by a movable breech-block, which slides in the line of the barrel by direct action. It is opened by raising the handle of the breech-bolt to a vertical position and drawing it back to its full extent. In raising the handle, the firing-pin is retracted by a lug near its head engaging with a spiral cam-recess in the receiver; it is held back by the lug enter ing a circumferential groove in the bolt. In withdrawing the bolt, it passes over the hammer and presses it back to the full-cock. The piece is closed by reversing the movement of the bolt. At the end of the forward stroke, the point of the ex tractor engages with a recess in a ring which surrounds the mouth of the chamber, and against which the bolt is pressed, and turns the ring with it ; so that the rota ' tion of the bolt in locking will not cause it to grind against the head of the car tridge. In turning down the handle, the piece is locked by the engaging of a
sectional collar on the bolt with a corresponding groove in the receiver. When this is accomplished, the lug on the firing-pin is opposite the deepest part of the spiral recess and is free to move forward when the piece is fired (by means of a center-lock moved by a double mainspring). Extraction is accomplished by a spring-hook lying on top of the breech-bolt ; and in drawing back the bolt, the natural spring of the extractor presses down the rim of the cartridge upon the 1 bottom of the receiver, until it is checked by striking against a notch left there for that purpose, and is thereby- thrown upward around the hook of the extractoi and clear of the gun.