Improvements in the Treatment of Rifle Barrels to Prevent them from Becoming Crooked while Firing.
Year: 1887

page_text: Date of Application, 15th Dec., 1887
Complete Specification Left, 15th Sept., 1888
Complete Specification Accepted, 19th Oct., 1888
Improvements in the Treatment of Rifle Barrels to Prevent them
from Becoming Crooked while Firing.
I, HIRAM STEVENS MAXIM, Mechanical Engineer, 57D Hatton Garden, London,
E.C., do hereby declare the nature of this invention to be as follows:-
When rifle barrels are made from solid bars of steel, the practice generally is to
drill them from one end, and as the hit runs out, to bend the barrel in the same
It sometimes
direction so as to keep the bit approximately in the center of the mass.
so happens that the bit runs much out of a straight line, and the barrel is bent in
a corresponding direction in order that the bit may come out approximately in the
center of the other end. When this occurs, the barrel is hammered cold until
the bore is approximately true. It is found in practice that when such barrels
become heated from rapid firing, they have a tendency to resume their original shape
thus throwing them considerably out of truth. It is also found that if a small portion
of the external steel be removed, the barrel also becomes crooked.
To prevent this, I treat the barrels in the following manner:
The barrels having been rifled and finished in the ordinary way, I mount the barrel
in a lathe, so that both the external and the internal surfaces run true; I then
pass a current of carbureted hydrogen gas through the bore, and at the same time
apply a series of gas flames to the external surface.
As the barrel becomes heated, it runs out of truth, and this is corrected from
time to time by straightening it by means of levers or mallets while it is in the
lathe and while it is hot, and while the current of gas is still passing through
the bore.
When a barrel is thus straightened, I find in practice that it does not become
crooked while firing and that the accuracy of firing is very much improved. The
current of gas passing through the bore effectually prevents any damage to the
riffing by oxidation. The current of gas also removes to some extent, the heat
from the interior of the mass, so that it cools rather quicker on the inside than on the
outside.

page_text: Improvements in the Treatment of Rifle-barrels to Prevent them
from Becoming Crooked while Firing.
I, HIRAM STEVENS MAXIM, of 571 Hatton Garden, in the County of Middlesex,
Mechanical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
In the manufacture of gun-barrels from solid bars of steel, the practice generally is
to drill or bore the said bars from one end to the other end thereof, and, should the
boring-bit run out of truth or deviate from a straight line through the centre of the bar,
to bend the bar in such a manner as to keep the said bit approximately in the centre
of the mass.
It sometimes happens that the bit runs out or deviates much from the
straight line, and the barrel has to be bent to a great extent in order that the bit may
come out approximately in the centre at the end of the bar. When this occurs, the
barrel is usually hammered while cold until the bore is approximately true.
It is found in practice that, when such barrels become lieated from rapid firing, they
have a tendency to resume the shape they had subsequent to the boring and previous
to the straightening operation, so that they are considerably distorted or deformed or
thrown out of truth. It is also found that, if a small portion of the external steel be
removed, the barrel also has a tendency to become crooked.
Now my invention is designed to obviate this defect. For this purpose I treat gun-
barrels in the following manner, that is to say -The barrel having been rifled, if
desired, and finished in the ordinary or other suitable manner, I mount the said barrel
in a lathe so that both its external and internal surfaces run true; I then pass a current
of carburetted hydrogen gas through the bore, and at the time apply a series of gas
flames to, or otherwise heat, the external surface of the barrel. As the barrel becomes
heated, it runs out of truth, and this is corrected from time to time by straightening
it by means of levers or mallets or otherwise while it is in the lathe and while hot,
the current of gas through the bore being maintained during this straightening
operation.
When a barrel is thus straightened, I find that it is not liable to become crooked
while firing and that the firing is very much improved in respect of accuracy of aim.
The current of gas passing through the bore effectually prevents any damage to the
rifling by oxidation, during the straightening operation, and also removes, to some
extent, the heat from the interior of the mass, so that it cools rather more quickly on
the inside than on the outside.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I wish it understood that
I claim -
The above described method of treating a gun-barrel to prevent distortion or
deformation thereof under the action of heat due to rapid firing of the gun.
Dated this 4th date of Santamber 1888
HIRAM STEVENS MAXIM.
Haseltine, Lake & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.
HIRAM STEVENS MAXIM.
Haseltine, Lake & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.