U.S. patent application number 11/750445 was filed with the patent office on 2011-02-17 for revolver for firing high velocity ammunition.
This patent application is currently assigned to SMITH & WESSON CORP.. Invention is credited to JOHN W. AVEDISIAN, BRETT CURRY, JASON ROBERT DUBOIS, SIMON MICHEAL MUSKA, GARY E. ZUKOWSKI.
Application Number | 20110035982 11/750445 |
Document ID | / |
Family ID | 37233055 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110035982 |
Kind Code |
A1 |
DUBOIS; JASON ROBERT ; et
al. |
February 17, 2011 |
REVOLVER FOR FIRING HIGH VELOCITY AMMUNITION
Abstract
A revolver for firing high velocity ammunition includes a frame,
a cylinder, a barrel, and a firing mechanism. The revolver may
include one or more of the following, each of which is especially
adapted for use in the context of firing high velocity ammunition:
spacers for adjusting a barrel-cylinder gap, for eliminating
broaching of the rearward surface(s) of the barrel; a forcing cone
formed in the rearward opening of the barrel for accommodating
deformed projectiles; a reflective surface (e.g., mirrored surface)
provided on the cone and/or barrel rearward surfaces, for reducing
erosion resulting from using high velocity ammunition; gain-twist
rifling in the barrel for a smoother transition to full projectile
velocity; a larger diameter, hardened firing pin bushing for
minimizing brass flow in the rearward direction; and a front sight
assembly that minimizes lateral shift or drift of the sight pin
during firing.
Inventors: |
DUBOIS; JASON ROBERT; (NORTH
SMITHFIELD, RI) ; MUSKA; SIMON MICHEAL; (ENFIELD,
CT) ; ZUKOWSKI; GARY E.; (INDIAN ORCHARD, MA)
; AVEDISIAN; JOHN W.; (WINDSOR, CT) ; CURRY;
BRETT; (CHICOPEE, MA) |
Correspondence
Address: |
MCCORMICK, PAULDING & HUBER LLP
CITY PLACE II, 185 ASYLUM STREET
HARTFORD
CT
06103
US
|
Assignee: |
SMITH & WESSON CORP.
SPRINGFIELD
MA
|
Family ID: |
37233055 |
Appl. No.: |
11/750445 |
Filed: |
May 18, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11270944 |
Nov 10, 2005 |
7254913 |
|
|
11750445 |
|
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|
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60627491 |
Nov 12, 2004 |
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Current U.S.
Class: |
42/65 |
Current CPC
Class: |
F41A 3/76 20130101; F41A
3/74 20130101; F41C 3/14 20130101; F41A 21/36 20130101; F41G 1/02
20130101; F41A 21/18 20130101 |
Class at
Publication: |
42/65 |
International
Class: |
F41C 3/14 20060101
F41C003/14 |
Claims
1-9. (canceled)
10. The firearm of claim 15, wherein: the primary member is disc
shaped.
11. The firearm of claim 15, wherein: a perimeter of the front face
is rounded.
12. The firearm of claim 15, wherein: a perimeter of the rearward
face is chamfered to facilitate the insertion of the firing pin
bushing in the recess.
13. The firearm of claim 15, wherein the firearm bushing further
comprises: a transition surface between the rearward face and an
outer wall of the seating member, said transition surface being
concavely radiused.
14. The firearm of claim 15, wherein: the rearward-most edge of the
seating member is chamfered to facilitate insertion of the firing
pin bushing into the recess.
15. A firearm for firing high velocity ammunition, the firearm
comprising: a frame; a barrel connected to the frame; a cylinder
pivotally attached to the frame and positioned within an opening in
the frame and having at least one chamber operatively aligned with
the barrel for housing a round of ammunition; and a firing pin
bushing connected to the frame, wherein the firing pin bushing has
a front face facing the at least one chamber, said firing pin
bushing including a generally cylindrical primary member defining
the front face and having a firing pin aperture extending there
through from the front face to a rearward face of the primary
member, and a generally cylindrical seating member extending from
the rearward face of the primary member and having a seating member
aperture extending there through, said seating member aperture
being concentrically positioned with respect to the firing pin
aperture and having a diameter greater than a diameter of the
firing pin aperture; wherein the firing pin bushing is mounted in a
recess in the frame complementary in shape to the firing pin
bushing; and wherein the recess includes a first vertical surface,
a first land, a second vertical surface and a second land, and a
chamfered rim defining an edge between the first land and the
second vertical surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 60/627,491, filed Nov. 12, 2004; and U.S.
Utility application Ser. No. 11/270,944, filed Nov. 10, 2005, both
of the foregoing hereby incorporated by reference in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to firearms and,
more particularly, to revolvers having modified structures that are
adapted for the firing of high velocity ammunition.
BACKGROUND OF THE INVENTION
[0003] High velocity ammunition is well known for use in rifles and
other long guns. Ammunition of this type is characterized by muzzle
velocities in excess of 2,500 feet per second (fps). Handguns,
however, have not been capable of muzzle velocities of this
magnitude, and have an upper bound of about 1,500 fps. Revolvers
present the added challenge of a barrel-cylinder (BC) gap to allow
for cylinder rotation. In such revolvers, the hot gases generated
by the ignition of the powder are vented out the cylinder and down
the barrel, with some venting at the BC gap, with a concomitant
loss of pressure and bullet velocity. The BC gap must be
established and uniformly maintained between the forward-most
surface of the chamber and the rearward-most surface of the barrel
to ensure that proper cylinder pressures are maintained during
firing. In revolvers in which the barrels are threaded to the frame
so as to extend through a rearward-facing portion of the frame,
methods for setting the BC gap include broaching the rearward
surface of the barrel after the barrel is threaded into the frame.
This broaching method produces tool marks on the end surface of the
barrel adjacent the cylinder and oftentimes mars the finish of the
barrel.
[0004] The use of high velocity ammunition causes a more powerful
and intense release of the high-pressure gases from the cartridge
casings upon firing. Correspondingly, a greater acceleration of the
bullet from the cartridge is realized with the projectile traveling
from the cylinder across the BC gap to the barrel. The greater
force necessary to achieve muzzle velocities in the range of 2,500
fps generates forces of a magnitude that can cause cartridge brass
to flow in a rearward direction and somewhat increased bullet
deformation. Standard geometries at the rearward end of the barrel
(at which the bullet enters) include tapered or chamfered surfaces
to facilitate the engagement of the deformed projectile. Standard
constant twist rifling allows the projectile to be sufficiently
engaged and longitudinally rotated at a constant rate as the
projectile traverses the length of the barrel.
[0005] Certain high-powered revolvers have a shroud placed over the
barrel and can therefore have a releasably secured sight assembly
mounted at the forward end of the shroud. Such sight assemblies
usually employ known mounting arrangements to ensure proper sight
alignment and positive sight retention. These replaceable sight
assemblies generally comprise sights with a dovetail base that are
urged by springs in the forward direction such that forward edges
of the sights engage laterally-positioned mounting pins. With this
releasable sight configuration, there sometimes is displayed an
undesirable lateral shift or drift of the laterally-positioned pin
due to the forces associated with high velocity ammunition. In such
cases, the sights correspondingly shift with the
laterally-positioned mounting pins.
[0006] What is needed is a revolver firearm that is capable of
reliably firing high velocity ammunition and that addresses these
and other special circumstances found with operating a handgun in
this extreme range of muzzle velocities.
SUMMARY OF THE INVENTION
[0007] An embodiment of the present invention relates to a firearm
for firing high velocity ammunition, provided in the form of a
revolver that includes a frame, a cylinder, a firing mechanism, and
a barrel, all of which are operably interconnected in a manner
similar to a standard revolver. For example, the cylinder is
pivotally mounted in the frame and includes a plurality of chambers
configured to receive and align cartridges with the barrel, while
the firing mechanism includes a trigger and a hammer, wherein upon
a user pressing the trigger in a rearward direction, the hammer is
operated to discharge a cartridge loaded into one of the
chambers.
[0008] One advantage of the revolver of the present invention is
that a space between a rearward portion of the barrel and a forward
surface of the cylinder can be adjusted longitudinally within a
shroud housing the barrel from a forward end of the barrel. Such
adjustment is typically effected by the use of one or more spacers.
By allowing the position of the barrel to be adjusted in such a
manner, the need to broach the rearward surfaces of the barrel is
eliminated.
[0009] Another advantage is that the barrel is provided with a
forcing cone integrally formed at the rearward opening thereof. The
forcing cone (and/or the rear surface of the barrel) can be
polished or otherwise finished to provide a reflective surface that
reduces the amount of erosion that can result from using the
revolver with high velocity ammunition. Thus, because the surface
of the cone is subject to less erosion, the barrel life of the
handgun can be extended. Furthermore, the geometry of the surface
of the cone in conjunction with the reflective finish allows the
projectile of the high velocity ammunition to show a smoother
translation across the BC gap, thereby showing improved performance
results in the revolver.
[0010] Another advantage of the present invention is the use of
gain-twist rifling in the barrel that allows for a more gradual
engagement of the high velocity projectile with the rifling and
further allows for a smoother transition to the full velocity of
the projectile as the projectile exits the barrel. Moreover, by
using a preferred electrochemical process to produce the rifling,
variations in land width and profile, as well as a smoother
transition to the full twist rate, can be realized.
[0011] Yet another advantage of the present invention is the
optional provision of a larger diameter, hardened firing pin
bushing that allows for improved support at the head of the
cartridge casing. By utilizing a larger bushing (e.g., a bushing in
which the diameter thereof is at least as large as the casing
head), brass flow in the rearward direction may be minimized when
high velocity ammunition is fired.
[0012] Still another advantage of the present invention is an
interchangeable front sight assembly with a lateral locating pin
having a dumbbell-shaped configuration. Such a configuration
minimizes lateral shift or drift of the sight pin during the firing
of high velocity ammunition from the handgun.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a simplified schematic representation of a handgun
made in accordance with the present invention.
[0014] FIG. 2 is a perspective view of a cylinder and ejector of
the handgun of FIG. 1.
[0015] FIG. 3 is a simplified schematic representation of the
handgun of FIG. 1 in exploded cutaway view.
[0016] FIGS. 4, 4A, and 5 are simplified schematic representations
of the handgun of FIG. 1 in cutaway view.
[0017] FIG. 6 is a simplified schematic representation of a barrel
of the handgun of FIG. 1 showing a forcing cone.
[0018] FIG. 7 is a simplified schematic representation of a barrel
of the handgun of FIG. 1 showing gain-twist rifling.
[0019] FIG. 8 is a perspective view of a portion of a frame of the
handgun of FIG. 1.
[0020] FIG. 9 is a perspective view of the frame of the handgun of
FIG. 8 showing a firing pin bushing mounted in a yoke of the
frame.
[0021] FIG. 10 is a perspective view of the firing pin bushing of
the handgun of FIG. 9 mounted in the yoke of the frame and shown in
cutaway view.
[0022] FIGS. 11 and 12 are perspective views of the firing pin
bushing for a revolver made in accordance with the present
invention.
[0023] FIG. 13 is a side elevation view of the frame and firing pin
bushing of FIG. 9.
[0024] FIG. 14 is a side elevation view of a front sight assembly
on the forward end of the barrel of a revolver made in accordance
with the present invention.
[0025] FIG. 15 is a perspective view of the front sight assembly of
FIG. 14.
[0026] FIGS. 16 and 17 are perspective and side elevation
cross-section views, respectively, of a bushing-less, hardened
frame according to an alternative embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to FIG. 1, one exemplary embodiment of a firearm
incorporating the present invention is shown generally at 10 and is
hereinafter referred to as "firearm 10." The firearm 10 is
preferably a revolver (as described in U.S. Pat. Nos. 6,330,761 and
6,523,294, which are incorporated herein by reference) that
includes a frame 12, a cylinder 14, a firing mechanism 16, and a
barrel 18. A firing axis 19 extends coaxially with the barrel 18.
High velocity ammunition is the preferred type of ammunition for
use in the firearm 10, such ammunition typically being capable of
attaining bullet muzzle velocities of about 2,500 feet per second
or greater.
[0028] The cylinder 14 is pivotally mounted in the frame 12 and
includes an ejector 20, a ratchet 22, and a plurality of chambers,
two of which are shown at 26. The chambers 26 are configured to
receive and align cartridges with the barrel 18. The cylinder 14 is
pivotally mounted on a yoke 28 that is attached to the frame 12. A
top strap 29 extends across a top portion of the frame 12 from a
forward portion to a rearward portion to define a generally
rectangular aperture. When the cylinder 14 is closed with respect
to the yoke 28, the cylinder 14 is positioned in the rectangular
aperture such that a chamber 26 of the cylinder 14 is
longitudinally aligned with the barrel 18. A retaining mechanism 30
maintains the cylinder 14 within the rectangular aperture. A
cylinder release bar actuated by a thumb piece 36 allows the
cylinder 14 to be rotated out of the rectangular aperture into a
cylinder-open position.
[0029] The firing mechanism 16 includes a trigger 40 and a hammer
42. Upon a user pressing the trigger 40 in a rearward direction,
the hammer 42 is operated to discharge a cartridge loaded into the
firearm 10.
[0030] Referring now to FIG. 2, the ejector 20 includes a rod 21
about which the cylinder 14 rotates. The ratchet 22 is attached at
a rearward end of the rod 21 and has a plurality of detent or cut
out portions 25 that correspond to the respective rearward edges of
each chamber 26. The ratchet 22 is dimensioned such that it is
received in a recess at the rear surface of the cylinder 14 so as
not to obstruct the rotation of the cylinder 14 on the yoke 28 or
the opening and closing of the cylinder 14 in the rectangular
aperture. Upon loading a cartridge into any chamber 26, a rim on a
base of the casing of the cartridge engages the cut out portion 25
of the ratchet 22. To eject cartridges from the cylinder 14, the
firearm is placed in the cylinder-open position and a forward end
of the rod 21 is urged in the rearward direction. The defining
edges of each cut out portion 25 engage the rims of the casings,
and the casings are pulled out of the rear of the cylinder 14.
[0031] Referring now to FIGS. 3-5, the barrel 18 is mounted in a
shroud 44 attached to a forward portion of the frame 12. (The
shroud 44 may be considered part of the frame 12, i.e., part of the
support structure of the firearm.) The barrel 18 comprises an
elongated, substantially cylindrical member having a cylindrical
bore 46 extending longitudinally there through. The surfaces of the
barrel 18, namely, the rearward-most edge surface at which the
projectile enters the barrel and the wall of the cylindrical bore
46, are polished or otherwise finished to provide a reflective
surface such that the hot gases generated during the firing of
ammunition are less likely to have an effect on the barrel
surfaces. For example, the reflective surface may be a highly
reflective surface (by which it is meant a surface with a
reflectance or albedo of at least 0.85) or a mirrored surface (a
reflectance/albedo of at least 0.95). Upon assembly of the
revolver, the cylindrical bore 46 registers with the respective
chambers 26 of the cylinder 14 and forms the longitudinal firing
axis 19.
[0032] The clearance between the forward-most surface of the
cylinder 14 and the rearward-most surface of the barrel 18 is the
barrel-cylinder (BC) gap. The barrel 18 is mounted in the shroud 44
using a spacer 48 positioned at a forward end of the barrel 18 to
give the desired BC gap (see FIG. 4A for a detail view). The spacer
48, which may be annular-shaped, washer like device, is positioned
against a flange 50 on the shroud 44. The fore end of the barrel 18
may also be provided with a flange 51 for abutting the spacer 48
when the firearm 10 is assembled. Alternatively, the spacer 48 may
be removably connected to the barrel in a standard manner. The
width of the spacer 48 is selected to give the desired BC gap.
Alternatively, two or more spacers 48 can be stacked together on
the barrel 18 to adjust the BC gap. Thus, because the BC gap is
adjusted via the spacer(s) 48, the threading of the barrel into the
frame and the broaching operation in which the rearward portion of
the barrel is cut off (potentially marring the polished barrel
surface) is avoided. A muzzle brake 52 (FIG. 5) fits over the
forward end of the barrel 18 and is positioned in the shroud 44.
The muzzle brake 52 is held in the shroud 44 using a screw 54 or
similar device.
[0033] Referring now to FIG. 6, a forcing cone 60 is integrally
formed with the barrel 18 at the rearward opening thereof. The
forcing cone 60, which accommodates for the deformation of the
projectile as the projectile traverses the BC gap, comprises a
rearward edge 62 that is defined by the perimeter of the rearward
opening of the barrel 18. The forcing cone 60 extends radially
inward toward the firing axis 19 to terminate at the inner wall 64
of the barrel 18. Thus, the forcing cone 60 has a slightly larger
entry diameter as compared to the central bore diameter of the
barrel 18, thereby providing a clearance between the cylinder and
the barrel 18 to facilitate movement of a projectile (e.g., bullet)
from the cylinder to the barrel 18. In particular, the slightly
larger entry diameter of the forcing cone 60 enables the projectile
to enter the barrel 18 with a reduced probability that the
projectile will engage a rearward-facing surface 66 of the barrel
18.
[0034] The rearward edge 62 of the forcing cone 60 is configured to
have a radius (e.g., it is rounded) to further facilitate the
movement of the projectile from the cylinder into the forcing cone
60. A forward edge 68 of the forcing cone 60 may be likewise
configured to have a radius to even further facilitate the movement
of the projectile from the forcing cone 60 to the barrel 18. A wall
70 of the forcing cone 60 adjacent the rearward edge 62 may be
provided with a reflective finish (e.g., a highly reflective or
mirrored surface) to allow hot gases to flow more smoothly and to
reduce the opportunity for the surface of the forcing cone 60 to
erode.
[0035] Referring now to FIG. 7, lands 74 and grooves 76 are
disposed on an inner wall 78 of the cylindrical bore 46 of the
barrel 18 to form gain-twist rifling. Gain-twist rifling is
characterized by a twist rate (turns per unit distance) that varies
along the length of the barrel from a slow twist at the breech/rear
end of the barrel to a tighter twist at the muzzle/fore end of the
barrel, e.g., from a slow rate such as one twist per 100 inches to
a higher rate such as one twist per 20 inches. The gain-twist
rifling of the present invention may be produced on the inner wall
78 using an electrochemical process that produces rifling in which
the width of the lands 74 increases as the twist rate increases,
thereby allowing more of the bullet surface to be engraved as the
bullet traverses the length of the barrel 18. Essentially, as the
lands get wider, the bullet is gripped tighter as it spins faster.
This is different from conventional grain-twist rifling, where the
full land and groove profiles are engraved initially, and then the
twist rate is increased. One exemplary electrochemical process for
producing rifling in gun barrels is disclosed in U.S. Pat. No.
5,819,400, which is incorporated herein by reference in its
entirety. Gain-twist rifling lessens the abrupt transition from
zero angular velocity to the nominal or maximum angular velocity.
The smoother transition up to the nominal or maximum angular
velocity has been found to increase accuracy by minimizing bullet
deformation as it engraves the rifling. Furthermore, users may feel
less recoil torque because of the bullets' smoother transition to
maximum angular velocity.
[0036] As noted, the lands 74 closest to the breech end of the
barrel (near the forcing cone 60) may be smaller in width. The
edges of these lands will typically not be as sharp as those of the
lands further down the barrel where the twist rate is increased. In
particular, the edges of the lands proximate to the forcing cone
may be provided with smoother or more rounded edges, as a result of
the electrochemical process or otherwise. This results in a
reduction of bore erosion ahead of the forcing cone.
[0037] Referring now to FIGS. 8-13, the firearm also incorporates a
firing pin bushing 80 having a diameter (or other widest dimension
if the bushing is non-circular) that meets or exceeds the diameter
of the head of the cartridge casing used in the handgun. As is
shown in FIG. 8, the firing pin bushing 80 is mounted in a recess
82 in a forward-facing, bolster face portion 81 of the frame 12.
The recess 82 is defined by a first vertical surface 84, a first
land 86, a second vertical surface 88, and a second land 90. A
chamfered rim 89 defines the edge between the first land 86 and the
second vertical surface 88. The lands and vertical surfaces of the
recess 82 are sufficient to accommodate the firing pin bushing 80
with a degree of precision such that the firing pin bushing 80 can
be mounted with a minimum amount of angular displacement from the
flush surface of the bolster face 81 at the upper portion thereof.
Referring to FIG. 9, a lower portion of the firing pin bushing 80
extends into a cavity or recess 91 in the bolster face 81.
[0038] Referring now to FIGS. 11-13, the firing pin bushing 80
comprises a primary member 92 having a planar front face 94, a
firing pin aperture 96 drilled, bored, machined, cast, or otherwise
formed in the center of the primary member 92 so as to extend
therethrough, and a seating member 98 extending from a rearward
face 100 of the primary member 92. The primary member 92 may be
disc- or plate-shaped, i.e., shaped akin to a washer or squat
cylinder, and the seating member 98 is preferably generally
cylindrical in shape and concentrically positioned relative to the
firing pin aperture 96.
[0039] The width dimension of the front face 94 is at least as
great as the diameter of a cartridge casing head used in the
firearm to prevent brass flow during the use of high-pressure
ammunition. As can be best seen in FIGS. 11 and 13, the perimeter
of the front face 94 has a radius, i.e., its outer edge is rounded.
The perimeter of the rearward face 100 (FIGS. 12 and 13) is
chamfered to facilitate the insertion of the firing pin bushing 80
into the recess. A transition surface 104 between the rearward face
100 and the outer wall of the seating member 98 is concavely
radiused to provide a space between the chamfered rim 89 and the
firing pin bushing 80. The rearward-most edge of the seating member
98 is chamfered at an angle of about 30 degrees to even further
facilitate the insertion of the firing pin bushing 80 into the
recess. As can best be seen in FIG. 13, the diameter of the
aperture of the seating member 98 is greater than the diameter of
the firing pin aperture. The aperture of the seating member 98
registers with a bore 108 in the yoke 28 through which the firing
pin (not shown) translates to extend through the firing pin
aperture 96 to engage a cartridge.
[0040] Referring to FIG. 14, the firearm incorporates a front sight
assembly 120 that is mountable into the shroud 44. The sight
assembly 120 of the present invention is an improvement on the
sight assembly of U.S. Pat. No. 5,802,757, which is incorporated
herein by reference in its entirety. The sight assembly 120 of the
present invention includes a sight 123 having a sight pin portion
121 and an anchor portion 122. The anchor 122 is attached to or
connected to the sight pin 121 via a connector 124, which is of a
lesser width-wise dimension than either the sight pin 121 or the
anchor 122. The anchor 122 is received in a slot 126 on the
uppermost surface of the forward portion of the shroud 44. The
anchor 122 and the receiving slot 126 extend longitudinally in the
direction of the longitudinal firing axis of the firearm. In
mounting the sight 123, the anchor 122 is press-fitted into the
receiving slot 126 such that the connector 124 and the anchor 122
engage a laterally mounted dumbbell-shaped pin 125 that is
positioned across the receiving slot 126 perpendicular to the
direction in which the slot 126 and the longitudinal firing axis
extend. A spring 130 mounted in the rearward portion of the
receiving slot 126 is configured to urge the anchor 122 (and,
accordingly, the connector 124 and the sight 121) in a forward
direction against the dumbbell-shaped pin 125.
[0041] Referring now to FIG. 15, the dumbbell-shaped pin 125
comprises a dowel-shaped connection member 131, a first protrusion
132 attached to a first end of the connection member 131, and a
second protrusion 134 attached to a second end of the connection
member 131. A forward surface of the connector is substantially
vertical and perpendicular to the longitudinal firing axis when the
sight 123 is mounted in the shroud. A forward surface of the anchor
122 is tapered such that when the connector 124 and the anchor 122
are attached to each other or integrally formed, an angle A is
defined. Upon urging the anchor 122 and the connector 124 against
the dumbbell-shaped pin 125, the dowel-shaped connection member 131
is received in a vertex of the angle A. The first protrusion 132
and the second protrusion 134 capture the anchor 122 and the
connector 124 there between, thereby facilitating the retention of
the sight assembly 120 in place.
[0042] FIGS. 16 and 17 show a "bushing-less" frame 140 according to
an alternative embodiment of the present invention. The frame 140
is not provided with an enlarged firing pin bushing 80 (as shown in
FIGS. 8-13) or other type of firing pin bushing. Instead, the frame
140 has a firing pin aperture 142 formed directly in the frame and
extending there through, and the area 144 of the frame around the
aperture (e.g., the bolster face 81) is hardened using standard
methods. Optionally, the entire frame 140 may be hardened. As
should be appreciated, traditional firing pin bushings present a
"seam" in the bolster face proximate the casing head, as between
the bushing and frame. With high velocity ammunition, the brass
casing may start to flow into the seam, jamming the cylinder. With
the enlarged bushing 80, the seam is moved away from the casing
head. With the bushing-less frame 140, the seam is eliminated
entirely.
[0043] Although this invention has been shown and described with
respect to the detailed embodiments thereof, it will be understood
by those of skill in the art that various changes may be made and
equivalents may be substituted for elements thereof without
departing from the scope of the invention. In addition,
modifications may be made to adapt a particular situation or
material to the teachings of the invention without departing from
the essential scope thereof. Therefore, it is intended that the
invention not be limited to the particular embodiments disclosed in
the above detailed description, but that the invention will include
all embodiments falling within the scope of the above
disclosure.
* * * * *