IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS, KNOWN AS CHASSEPOT RIFLES
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Henry Carter and George Henry
Edwards at the Office of the Commissioners of Patents, with their
Petition, on the 1st April 1869.
We, HENRY CARTER, and GEORGE HENRY EDWARDS, both of Bow,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS, KNOWN AS
CHASSEPOT RIFLES," to be as follows:-
This Invention relates to certain improvements in the construction
of that description of fire-arm known as the ordinary or improved
Chassepot breech-loading rifle, whereby the Boxer or Daw cartridge may
be used instead of the French cartridge, an extractor being applied
directly to the closing bolt of the arm.
The improvements are applicable to the primary manufacture of the
gun, or to the conversion of the ordinary or improved Chassepot rifle.
In the improvement on his original gun, Mr. Chassepot devised a
means whereby a central percussive fire cartridge could be used and
discharged by a striker, instead of his original penetrating needle; he
also applied an extractor consisting of a slotted flat plate, having a

page_text: curvilinear notch at its extremity to grip the rim of the cartridge, and
into this slotted plate a tooth on the sliding bolt was caused to enter,
and thus when the bolt was nearly drawn back from the breech to its
full extent the tooth geared with the slotted end of the extractor, and
withdrew the metallic end of the cartridge to the extent of about half a
an inch, merely sufficient to extract the detonator, the fore part of the
cartridge case having been exploded by the discharge.
This arrangement could not be applied to the Boxer or Daw cartridge
because it would in such case be necessary to withdraw the entire case
of the cartridge from the breech, and moreover the arrangement of
the breech itself in the improved Chassepot does not permit the use of
the Boxer or Daw cartridge.
The extractor in Chassepot's improvement is a sliding extractor sepa-
rate from and independent of the bolt, and deriving motion from the
tooth below the bolt; but by our improvements in the breech and
extractor we are enabled to render the original and improved Chassepot
capable of using the Boxer or Daw cartridge, neither of which it has
hitherto been capable of firing and extracting.
In order to adapt the Boxer or Daw central-fire cartridge we first alter
the bore of the breech end of the barrel in so far as the reception of
the cartridge is concerned.
In the primary manufacture of the gun this alteration of the form
of breech would be made direct, but in the process of conversion we
accomplish the change in the following manner:-We take an exact
model of the original form of breech, in rear of the rifling, that is to
say, so much of the bore and cavity of the breech behind it as is
necessary to constitute the receptacle or space for the cartridge when
the arm is loaded, and from this model we form a corresponding metallic
plug or stopper of similar shape and dimensions; this we subject to
a red heat and insert it firmly into the breech and rear of the cavity
or shoe close to the breech, so as to close or plug the same, we then
bore or drill through the body or sides of the barrel two apertures a short
distance apart and at right angles each to each, passing completely
through the sides of the barrel and plug, and we then insert two screws
(forming screw rivets by hammering) which serve to secure the plug
in position. We then rebore the breech through this plug, in order to
form within the plug a new breech of a partly parallel or cylindrical
form to suit the shape of that portion of the cartridge containing the

page_text: powder, and terminating in a curved or somewhat conical and gradua-
ting form to suit the bullet end and comply with the requirements of
the rifle grooves of the Chassepot gun; or the cartridge may be of a
complete taper from end to end. In other words we bore the plug to
suit the Boxer cartridge and enable it to fit such altered bore and to
leave an annular surface of stop or contact for the rim of the cart-
ridge to bear upon when it is thrust home into the breech by the action
of the sliding bolt ready for discharge. The breech having thus become
contracted, and a flush annular surface being left for the reception of
the cartridge rim, we then enlarge the cavity of the open breech (to
suit the requirements of our improved extractor hereafter described) by
cutting out a dip at the bottom of the groove or shoe close to the breech
and extending beneath the position of the cartridge rim when inserted.
We continue this enlargement by cutting away a circular sweep towards
the left hand side of the interior of the open breech and around the left
side of the rear extremity of the plug (when the gun has been converted),
or similarly when the gun is primarily manufactured in a correspending
form, in order to permit the point of the extractor to turn with the
bolt when the bolt is operated by the handle, the extractor being fixed
by means of a spring and screw to the bottom of the sliding piston or
bolt which drives home the cartridge. When the extractor which
projects from the sliding bolt presents its tapering or wedge surface
to the under edge or rim of the cartridge it is necessary in order that
the lock or notch of the extractor shall grip the rim that the extractor
must first descend or dip into the enlarged shoe of the arm, otherwise
it would jam or wedge itself between the shoe or groove and the
cartridge, and would not freely pass between the two; this dip
of the extractor is therefore permitted by the enlarged cavity referred
to, and when the cartridge has been discharged the sliding bolt must
be turned and drawn back to extract the cartridge for reloading. This
turn of the bolt could not be effected by the fixed extractor thereon
unless the circular enlargement of the open breech on the left of the
arm and interior of the open breech had been made. Since it is
necessary to dispense with the discharging needle as used in the first
Chassepot rifle, in order to apply and discharge the central percussion
cartridge of Boxer or Daw we substitute a striking pin and shorten
the stroke of the discharge, so that the pin when the trigger is pulled
only projects slightly from the cavity or bore in the bolt just sufficient
to operate on the detonator; this plan is of course necessary, but as

page_text: Chassepot has already adopted it in his improvements it forms no part
of this Invention. The sliding bolt is to be shortened by the removal
of the small stem or projection of the Chassepot, which originally enter el
the barrel and made contact with the cartridge, so that we enable the
full diameter and area of the sliding bolt to bear firmly against the
metallic rear of the cartridge and force it home against its bearing on
the plug or enlargement of the breech.
It will be particularly observed that the extractor is a fixture to the
sliding bolt, and acquires all the movements of the bolt simultaneously
whether advancing, retrograding, or turning; whereas in the improved
Chassepot the extractor is separated from the bolt and slides in a groove
cut in the shoe, but with our extractor no groove is required to be cut
in the shoe for the guidance or travel of tlie extractor, which is let in
a slot cut in the sliding bolt itself, in which it is secured by the screw.
When the Boxer cartridge is formed with a tapering surface nearly from
end to end only about an eighth of an inch of the case is subject to
friction in the insertion and extraction, and thus the extractor has
only to give an initial withdrawal instead of a continuous tension as is
the case when the cartridge case is cylindrical for a considerable portion
of its length.