IMPROVEMENTS IN RIFLED GUN BARRELS, AND IN THE MACHINERY FOR RIFLING GUN BARRELS
Year: 1879

page_text: LETTERS PATENT to Henri Pieper, of Liege, in the Kingdom of Belgium,
for the Invention of "IMPROVEMENTS IN RIFLED GUN BARRELS, AND IN THE
MACHINERY FOR RIFLING GUN BARRELS."
"
PROVISIONAL SPECIFICATION left by the said Henri Pieper at the Office'
of the Commissioners of Patents on the 30th October 1879.
HENRI PIEPER, of Liege, in the Kingdom of Belgium. IMPROVEMENTS IN
RIFLED GUN BARRELS, AND IN THE MACHINERY FOR RIFLING GUN BARRELS."
This Invention of improvements in rifled gun barrels, and in the machinery for
rifling gun barrels, relates to the form given to the interior of the barrel, and to
the machinery for producing that form.
It has been usual to bore fowling pieces to give them a long reach, and to enable
"choke bore."
them to concentrate the shot with a special form generally called a
The general form of my improved barrel with a "choke bore" is as follows:-
The barrel narrows a little, but as regularly as possible, from the cartridge chamber
to the middle of its length, continuing from here cylindrically until a few inches
from its muzzle, where it rapidly narrows either in the form of a regular cone or
in an oval form. This narrowing of the muzzle is from one to four sizes of bore
according to the degree of concentration wanted.
By adding my apparatus to the rifling machine I can obtain the inside form of
the barrel of whatever design may be required.
This apparatus is composed of a tube fixed on the end of the rifling machine in
In this tube a
a spring bearing, placed exactly in the axis of the rifling cylinder.
cylinder moves which is fastened to a regulating screw of the rifling cylinder.
This cylinder has a pivot which works in a groove of the tube, the groove runs the
whole length of the tube, sometimes in a regular spiral more or less rapidly turning
to the right or to the left, sometimes in an irregular curve, as one wishes to obtain
by the hook or cutter of the rifling cylinder a planing or cut straight, or conical
or oval inside of the barrel.
Then the pivot in following the groove turns the cylinder as soon as the groove
deviates from the straight line, and the cylinder turns the more quickly, as the
gradient of the groove is ranid.

page_text: The cylinder being fastened to the regulating screw of the rifling cylinder makes
the screw turn to the right or to the left, according to the form of the groove, and
in turning makes a rod united with the regulating screw go forward or backward.
This rod at its lower end forms an inclined plane on which lays the head of the
rifling book. This hook forming at one point a hinge, the edge goes up or down
according to the displacement of the inclined plane of the rod. The edge of the
hook runs in a line determined by the groove of the tube, and this groove is traced
so as to obtain the cut after the pattern is required. When another pattern is
required the tube is substituted for another having a groove conformable to the new
pattern.
This kind of rifling is preferably straight, that is to say, without twist. In order
to maintain the rifling cylinder in the centre of the barrel during the rifling the
interior of the barrel is left with a few ribs, the summits of which retain the
primitive size of bore of the barrel from one end to the other. The choke is
therefore only produced in the space between the ribs. These ribs, besides
maintaining the rifling cylinder, have these advantages,-The barrel can be fired
with ball, the size of the bore remaining uniform on the summit of the ribs.
When shot is used the ribs keep the wad in the right position and prevent it
turning in the barrel, they also prevent the shot from turning in the barrel, a great
advantage in firing, especially with big shot.
The space between the ribs can be made smooth with a hook of the same width,
or with different fine rifling with a small hook.
The two kinds produce the same effect.
The choke can also be produced at the
muzzle by boring and use the rifling only to widen the barrel towards the breech
end.
The rifling with deep groves and small projecting ribs can also be advantageously
used in a cylindrical manner without choke towards the muzzle, but the firing does
not produce the same extra good result as with the choke rifle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henri Pieper in the Great Seal Patent Office on the 14th February
1880.
HENRI PIEPER, of Liege, in the Kingdom of Belgium. "IMPROVEMENTS IN
RIFLED GUN BARRELS, AND IN THE MACHINERY FOR RIFLING GUN BARRELS.".
To give to the barrels of fowling-pieces a longer reach, and to concentrate the
shot more, one gives to the inside of the barrel a special form, generally designed
by. "choke bore." The general form of a barrel with choke bore is as follows:-
The barrel narrows a little, but as regularly as possible, from the cartridge
chamber to the middle of its length, continues from here cylindrically until a few
inches from its muzzle, where it rapidly narrows either in the form of a regular
cone or in an oval form (see Figures I and III., Sheet I). This narrowing at the
muzzle is from 1 to 4 sizes of bore, according to the degree of concentration wanted.
I have found out how to obtain that inside form of the barrel after whatever
design, directly with the rifling machine, by adding to the machine the apparatus
C, Sheet II. This apparatus is composed of a tube D fixed on the end of the
machine in a spring bearing E, placed exactly in the axis of the rifling cylinder F.
In this tube D a cylinder G moves which is fastened to the regulating screw H of
the rifling cylinder F. This cylinder G has a pivot J which works in a groove K
of the tube D. This groove, runs in the tube D in all its length, sometimes in a
straight line, sometimes in a regular spiral, more or less rapidly turning to the
right or to the left, sometimes in an irregular curve, as one wishes to obtain by the
hook L of the rifling cylinder F a planing or cut straight, or conical or oval
inside of the barrel. Then the pivot J in following this groove K turns the
cylinder G as soon as this groove deviates from the straight line, and the cylinder
turns the more quickly as the gradient of the groove is rapid. The cylinder G
being fastened to the regulating screw H of the rifling cylinder F makes that screw
turn to the right or to the left, or keeps it fixed, according to the form of the
groove, and in turning makes the rod M united with the regulating screw H at the
point N go forwards or backwards. This rod at its lower end forms an inclined
plane O, on which lays the head of the rifling hook L. This hook forming a hinge
in the point P its edge R goes up or down according to the displacement of the
inclined plane of the rod M. The edge of the hook runs in a line determined by
the groove K of the tube D, and one traces this groove so as to obtain a planing or
cut after the pattern required. When one wishes to obtain a planing of another
pattern, one substitutes the tube D by another, having a groove conformable to the
new pattern.
This kind of rifling is in preference straight, that is to say, without turning (see
Sheet I.). In order to maintain the rifling cylinder in the centre of the barrel
during the rifling, one leaves in the barrel several very small ribs, on the summit
(top) of which the barrel keeps its primitive size of bore from one end to the other
(see A, B, Sheet I.). The choke rifle is therefore only produced in the space between
the ribs. These ribs, besides maintaining the rifling cylinder, give the following
advantages-They allow the barrel to be fired with a ball, the size of bore remaining
uniform on the summit of the ribs. On firing with shot these ribs keep the wad
in a right position and prevent its turning in the barrel; they prevent also the
shot from turning in the barrel, a very great advantage for the result of firing,
especially with big shot.
The space between the ribs can be made smooth with a hook of the same width,
or with different fine riflings with a small hook (see A, B, Sheet I.). The two
kinds produce the same effect.
One can also produce the choke at the muzzle of the barrel by boring, and using
this rifling only to widen the barrel towards the breech end (see Figure II., I.).
This rifling with deep grooves and small projecting ribs can also be advantageously

page_text: used in a continuous cylinder without choke towards the muzzle; however the firing
does not produce the same extra good result as the choke-rifle.
Having now described and particularly set forth the nature of the said Invention
and the manner of carrying the same into effect, I would have it understood that
what I claim is,―
First. The choke made by a rifling machine in the form and design substantially
as described.
Second. The form of the rifling (A, B, Sheet I.) with deep grooves and small pro-
jecting ribs even if used in a continuous cylinder for barrels fired with shot,
substantially as described.
Third. The apparatus C added to the rifling machine to produce the choke-rifle,
substantially as described.
In witness whereof, I, the said Henri Pieper, have hereunto set my
hand and seal, this Tenth day of February, in the year of our Lord One
thousand eight hundred and eighty..