IMPROVEMENTS IN FIRE-ARMS AND PROJECTILES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Perceval Moses Parsons at the
Office of the Commissioners of Patents, with his Petition, on the
3rd December 1859.
I, PERCEVAL MOSES PARSONS, of Arthur Street West, London Bridge, in
the County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN FIRE-ARMS AND PROJECTILES," to be as
follows:-
In the construction of fire-arms, I form the breech end of the barrel, or the
frame to which it is attached, with a slat or recess, into which a moveable
breech containing the chamber for the reception of the charge is fitted. The
moveable breech is mounted on a pin or pivot at or near its rear end, against
which a screw works, and to which it is held by a pin or otherwise. The
screw takes into a female screw in the rear of the barrel or frame, or into an
adjusting nut or bush secured therein; a cam or eccentric attached to the
screw near the pin or pivot works against the rear end of the moveable
breech, which is made of a suitable form to admit of its so doing; the other
end of the screw has a lever attached to it for the purpose of turning it by
hand. When it is desired to load the piece, the screw is turned by means of
the hand lever so as to screw it back, and as it recedes it brings with it the
pin or pivot and the moveable breech, the cam at the same time, by its action

page_text: on the latter, causes it to turn slightly on the pin or pivot, and expose the
chamber. The charge being then introduced, the screw is turned the reverse
way; this immediately releases the cam, the breech drops, or is pressed by the
cam (acting the reverse way) into its proper position, and is finally forced by
the pressure of the screw against the barrel, thereby making good the joint
when the piece is ready to be discharged. In some cases I modify the above
arrangement by mounting the barrel itself on a pivot or trunnions, and impart
the requisite motion to it by means of the cam & the intervention of a lever
or other mechanical contrivance, the breech against which the screw acts being
in this case simply a plug which closes the end of the barrel.
For the purpose of rifling the barrels of fire-arms, I make the bore of a
section formed by three curved lines joined alternately by three other curved
lines of a different radius or curvature from the three first, and meeting them
at tangents; these together form a circular figure slightly flattened at three
points, and slightly bulged at the three opposite points. This figure changes
its position round its mean centre as it traverses the length of the barrel, &
thus gives the bore the requisite spiral twist. In constructing the back sights
of rifles, I form on the sides of the barrel, at the point where the back sight
is to be placed, two flat surfaces parallel to each other, and the plane of the
axis of the barrel and the centre of the foresight to which I fit a spring clip
or strap, which forms the back sight; this is made to clasp and slide upon the
flat surfaces, so that it can be moved up or down by hand to adjust it to any
elevation required. The sight is kept in position by shoulders or stops which
form guides or grooves for it to slide in.
In the construction of projectiles, I make them of a form more or less
conical or pointed at bothe ends, but I make the fore part of a substance of
greater specific gravity than the after part, the two being connected or united
together in any convenient manner. In constructing rifle bullets, I make the
fore part of lead or other suitable metal or alloy, and the after part of hard
wood or other suitable substance of less specific gravity than the fore part, the
after part having a plug which fits into a corresponding cavity in the fore part,
the two when together producing the form before described. To cause
expansion of the bullet, I provide the after part with a shoulder, which abuts
against the base of the fore part; and to afford lubrication, I insert between
the base of the fore part and the shoulder of the after part any suitable grease
or lubricating material, or an annular disc of felt, wadding, or other suitable
absorbent material saturated with oil or grease, when on the discharge of the
piece the oil or grease will be squeezed out by the after part of the bullet
being driven against the fore part.

page_text: For the purpose of imparting to rifle bullets increased hardness and
strength, as well as to reduce friction & prevent the leading of the barrel, I
make them, or the heavy parts of them of an alloy composed of lead and
antimony. From five to ten parts of antimony, mixed with one hundred
parts of lead, will generally be sufficient for this purpose, but I do not confine
myself to these exact proportions.