Improvements in Projectiles.
Year: 1899

page_text: Improvements in Projectiles.
I, HIRAM STEVENS MAXIM, of 18, Queen's Gate Place, in the County of
Middlesex, Chevalier of the Legion of Honour, Civil and Mechanical Engineer,
do hereby declare the nature of this invention to be as follows:-
66
This invention has reference to projectiles especially those which are used
with small arms and which are adapted to spread or
25
mushroom on impact.
Projectiles of this kind are now generally constructed with a covering or casing
composed largely of nickel and with a longitudinal cavity in the head or nose
thereof, which cavity is sometimes filled with plastic material. Such projectiles
have given satisfactory results when used with charges of black powder but when
used with charges of cordite or other smokeless powder giving high velocities,
the conditions under which these projectiles are used, are much changed. It
is well known that nickel and steel are very apt to adhere together when subjected
to heavy pressure; that is to say the co-efficient of friction existing between
clean steel and nickel is very high. It therefore oftentimes happens with
ammunition charged with smokeless powder and having nickel-cased projectiles,
that the friction between the nickel casing and the bore of the steel barrel, when
the projectile is subjected to the pressure of the gases on firing, is so great that
the nickel casing adheres to the barrel and permits the lead portion of the pro-
jectile to be forced from the said casing, the latter remaining in the barrel and
so rendering the fire-arm useless for subsequent firing until the casing has been
removed. It is the chief object of my present invention to overcome the above
stated objection.
For this purpose instead of providing a plain hole in the nose of the nickel
casing, I form said hole of somewhat less diameter than usual and turn its edge
inwardly to obtain an internal flange. Within the casing I place a hard metal
cap of considerable strength and thickness which covers the hole in the nose of
the casing and which is Hanged or otherwise formed at its periphery to firmly
engage with the aforesaid internal flange on the casing and thereby act to prevent
the portion of the casing at the nose from opening when the projectile is sub-
jected to the pressure of the powder gases. The lead portion of the projectile
is thus securely retained in its casing notwithstanding the friction, above
referred to, that exists between said casing and the barrel when the rifle is fired.
The lead portion of the projectile is formed with the usual longitudinal cavity
which may be either cylindrical or taper and which may be of any desired shape
in cross-section as for instance star-shape; such longitudinal cavity being if
necessary filled with plastic material such as paraffin wax.
In some cases, where it is desirable that the projectile should expand or be
torn to pieces on impact at comparatively low velocities, I may provide at the
bottom or other appropriate part of the aforesaid hole, an enlarged space which
not only serves to weaken the projectile at the part where such enlarged space
is formed but also presents an increased surface for the paraffin wax to act upon,

page_text: on impact of the projectile and thereby augments the tendency of the projectile
to expand or mushroom."
In order to enable such enlarged space to be conveniently formed, the lead
portion of the projectile may be divided transversely into two parts which are
adapted to fit together when inserted into the nickel casing, the said parts being
provided at their abutting ends with recesses which, when said parts meet, form
a complete cavity or enlargement around the longitudinal hole in the nose of
the projectile.
The nickel casing may be secured to the lead portion of the projectile in the
ordinary and well known manner.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, HIRAM STEVENS MAXIM, of 18, Queen's Gate Place, in the County of
Middlesex, Chevalier of the Legion of Honour, Civil and 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:
1
This invention has reference to projectiles and especially to those which are
adapted to spread or "mushroom" on impact and which are sometimes called
Express ΟΙ "Dum-dum". bullets.
"
Projectiles of this kind are now generally constructed with a covering or
casing composed largely of nickel and with a longitudinal recess or cavity in
the head or nose thereof, the said cavity being sometimes filled with plastic
material such as paraffin wax. Such projectiles have given satisfactory results
when used with charges of black powder but when used with charges of cordite
or other smokeless powder giving high velocities, the conditions under which they
are used are much changed and less satisfactory results are obtained. It is
well known that nickel and steel are very liable to adhere together when sub-
jected to heavy pressure; that is to say the co-efficient of friction existing
between steel and nickel is very high. It therefore oftentimes happens that
when the projectile is subjected to the pressure of the gases on firing, the friction
between the nickel casing and the bore of the steel barrel, is so great that the
casing adheres to the barrel and permits the lead portion of the projectile to be
forced from the said casing, the latter remaining in the barrel and so rendering the
fire-arm useless until the casing has been removed therefrom. It is the chief
object of my present invention to overcome this objection.
For this purpose I form in the nose of the nickel casing at the part surrounding
the mouth of the aforesaid longitudinal recess, a hole with an internal flange and
I provide within the casing a metal cap which covers and engages with the
aforesaid internal flange, thereby acting, when the projectile is subjected to the
pressure of the powder gases, to prevent the spreading or opening of the casing
at the nose, without however unduly retarding the expans on of the projectile
on impact, as hereinafter explained. The lead of the projectile is inserted into
the casing in the ordinary manner and is securely retained therein by the afore-
said metal cap, notwithstanding the friction, above referred to, that exists
between said casing and the barrel when the rifle is fired.

page_text: To ensure the effective expansion or "mushrooming" of the projectile on
impact I form in the body portion, (in addition to the aforesaid longitudinal
recess) transverse slits, passages or spaces which do not however extend through
the casing. The said recess and the transverse slits, passages or spaces are pre-
ferably all filled with paraffin wax or other suitable material of a plastic nature.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings, wherein I have illustrated, in transverse and vertical
section, several forms in which my improved projectile may be made.
A is the nickel casing and a is the internal flange thereof. B is the lead or
body portion. C is the cap and D the central longitudinal recess in the nose
of the projectile. The cap is made of hard metal of considerable strength and
thickness and its flanged periphery e engages with the internal flange a on the
casing A, so as to resist the tendency of the casing to open or spread at the nose
when the projectile is subjected to the pressure of the powder gases on firing,
as hereinabove stated. The aforesaid cavity D is filled with the paraffin wax
or other plastic material. The flanges a and c are in the example illustrated
made straight, so that while they will efficiently serve to prevent the opening
of the metal casing at the nose of the projectile when the gun is fired, their dis-
engagement will not be unduly resisted when, on impact of the projectile with
a soft body, the metal surrounding the recess D, by reason of its momentum
tends to advance relatively to said plastic substance and the cap C. That is to
say, on impact, the sail cap will remain stationary while the lead portion of the
projectile continues to advance, whereby said cap will compress the plastic sub-
stance, by receding relatively to the nose of the projectile. It will therefore
become disengaged from the flange a and at the same time the compression of
the plastic substance will cause a radial pressure on the metal surrounding the
recess D which will assist in expanding or spreading the projectile. From this
consideration of the action of the projectile on impact with a soft body, it would
appear that the said cap C not only operates to release the metal casing at the
nose of the projectile but also operates on the plastic substance as a piston or
plunger to cause said plastic substance to assist in expanding or spreading the
projectile.
The recess D may be either cylindrical or taper and may be of any desired
shape in cross-section. It will be found advisable to weaken the nose of the
projectile at the parts adjacent to the recess D), to diminish its resistance to
expansion or spreading on impact. For this purpose I form radial slits d in
the metal surrounding said recess, as represented in Figures 1 and 2. In
Figures 3 and 4 I have shewn the said slits extending transversely completely
through the lead portion and in Figures 5 and 6 I have shewn transverse
passages extending from the recess D) to the exterior of the lead portion. In
this figure I have also shewn the recess D) prolonged a considerable distance into
the lead portion. These cavities slots and passages, like the recess D, are pre-
ferably filled with the paraffin wax or other suitable plastic material. It is to
be observed that the aforesaid slits. passages and the like for weakening the nose
of the projectile, do not extend into the substance of the metal casing A.
In some cases, where it is desirable that the projectiles should expand or
spread on impact, at comparatively low velocities, I provide at the bottom or
other appropriate part of the aforesaid recess D) an enlarged space, such as that
shewn at in Figures 7 and 8, which space not only serves to weaken the pro-
jectile at such part, but presents an increased surface for the action of the plastic
substance when it is compressed on impact as aforesaid, and thereby augments the
tendency of the projectile to expand.
In order to enable such enlarged space to be conveniently formed, the lead
portion B may be made in two parts B1 B2 (as illustrated in Figure 8) which
parts, when inserted into the nickel casing fit together as shown and so form
the aforesaid space.

page_text: In the manufacture of the said projectile I prefer to first make the casing A
with its in-turned or flanged opening and then to insert the aforesaid cap C
into proper position for its flanged periphery to engage with the flanged opening.
The lead portion of the projectile with its recess D and its cavities d d¹ or d³
filled with the paraffin wax, is then inserted into the casing by hydraulic or
other pressure, while the said casing is enclosed and firmly held in a mould or
die in the well known manner, the edge a¹ of the said casing being finally
turned inward upon the base of the lead portion of the projectile as usual.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. A projectile of the kind herein referred to, in which the casing at the mouth
of the longitudinal recess, is prevented from opening or spreading on the firing
of the gun by a cap or similar retaining piece which on impact tends to change
its position relatively to the nose of the projectile for the purposes specified.
2. A projectile provided with a metal casing internally flanged at the nose
to receive a metal cap or similar retaining piece which is situated at the mouth
of a recess containing a plastic substance substantially as and for the purposes
specified.
3. A projectile consisting of a longitudinally recessed body enclosed in a casing
and formed with transverse slits, passages, spaces or the like, which do.not extend
through the said casing and which may or may not contain paraffin wax or other
suitable plastic substance for the purpose specified.
4. A projectile constructed substantially as described with reference to any
of the examples illustrated in the accompanying drawings, for the purposes
specified.
1
D 1 1
TA 1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.