A. Field of the Invention
The present invention relates generally to rifle accuracy and, more particularly, to a method for improving the accuracy of rifles when shooting at a fixed distance, using varying velocity ammunition and when shooting in differing atmospheric conditions. In another aspect, the invention relates to a noise suppressor design for such a rifle.
B. Description of the Prior Art
There has always been a desire among marksmen for firearms to be as accurate and consistent as possible during firing. This desire is particularly characteristic of marksmen who engage in rifle target shooting competitions and so-called “bench rest” competitions. As a result, the prior art is replete with efforts to eliminate or at least minimize those factors that adversely affect rifle accuracy. Two factors which have been studied extensively in the past are: (1) the barrel vibration which occurs upon firing of the weapon; and (2) the recoil which the marksman absorbs upon firing the weapon. Attempts to eliminate or control barrel vibration and recoil have involved a variety of materials and techniques. For example, various types and kinds of bedding materials have been used as a shock absorber and dampener between the barrel and the action assemblies and stocks of a rifle. The kinds and positioning of mounting screws associated with the components of a rifle have been examined. Different stock and barrel configurations have been tried in the past.
Muzzle brakes are another type accessory which have been used in the past with rifles in an attempt to lessen the effects of recoil and thus improve accuracy. The known muzzle brakes function to exhaust propulsion gases as a means of reducing recoil and of dissipating propulsion gases in a direction or directions other than directly out the muzzle of the barrel.
Another approach to improving rifle accuracy has involved attaching a weight to the end of the muzzle as a means of dampening barrel vibrations set in motion by the discharge of the firearm. U.S. Pat. No. 4,726,280, for example, discloses a technique for improving rifle accuracy by mounting a muzzle member on the muzzle end of a gun barrel. RE. 35,381 describes the Browning BOSS™ ballistic optimizing system which uses a movable weight element secured to the muzzle end of a rifle barrel. The weight element can be moved axially along the muzzle region of the barrel to change the effective weight applied for vibration dampening purposes.
U.S. Pat. No. 5,423,145 describes a rifle barrel harmonic vibration tuning device in which a “contact means” is adjustably positionable along the underside of the rifle barrel. The contact means exerts a variable amount of pressure between the rifle stock and its barrel at any of a number of given position along the barrel in an attempt to control the barrel's harmonic vibrations. U.S. Pat. No. 3,340,641 is similar in its disclosure and shows another sliding contact member which is used in an attempt to control the harmonic vibrations of the rifle barrel.
Despite these various types of efforts, deficiencies continue to exist in achieving ultimate rifle accuracy. This is particularly true when firing of certain factory loaded cartridges with a barrel not designed specifically for use with that cartridge. For example, with a lower velocity ammunition, the bullet tends to leave the barrel later than a faster velocity ammunition. As a result, due to the force of recoil, the bullet exits the muzzle at a point at which the rifle barrel has risen upwards more than it would with the faster velocity ammunition. The bullet shot from the lower velocity ammunition will thus tend to strike the target higher than the higher velocity ammunition, at a certain fixed distance.
A need exists, therefore, for a method for improving rifle accuracy which could be “tuned” to compensate for ammunition of varying velocities, particularly when shooting at a fixed distance. This would be advantageous, for example, in bench rest competitions and in certain military situations.
While there are many “tuners” on the market today, the tuning achieved or converging of different velocities is only effective out to about 100 yards. It is not possible to completely converge different velocities at long ranges out to extreme ranges, e.g. 1000 yards, or more.
There is also a need in the arena of tactical firearms that are utilized by the military as well as law enforcement tactical and special operations personnel for military and law enforcement activities, to provide a noise suppressor for such weapons. Noise suppressors are also used in some civilian circumstances, as well, as will be explained.
As is well known who are familiar with and enjoy firearms, firearms create both a loud noise as well as a significant recoil when they are discharged. The noise and the recoil are generally proportional to the size of the bullets being discharged by the firearms. For example, a 22 caliber rifle produces less noise and recoil than does a high caliber hunting rifle such as a 30-06 caliber firearm. However, both large and small bore weapons generally produce an undesirably great noise and recoil when discharged. This is true with respect to almost all firearms including both rifles and pistols.
Noise suppressors, sometimes referred to as “silencers’ for firearms have been proposed and made for many decades. Noise suppressors are very popular on varmint rifles because one shot drives varmints underground for hours while noise suppressed rifles can be fired many times before the game becomes wary. The standard noise suppressor was originally proposed by Hiram Maxim and present commercially available silencers are manifest descendants. These suppressors are mounted on the muzzle end of a firearm so the round or shot and all propellant gases pass through the suppressor. Most present day suppressor designs are basically mufflers. Disclosures of these typical firearm noise suppressors are found in U.S. Pat. Nos. 916,885; 958,934; 958,935; 1,229,675; 2,449,571; and 3,713,362.
Rifle suppressors are typically threaded onto the outer end of a firearm barrel in order to reduce the noise of the firearm. These devices generally work to muffle or reduce the noise of the exhausting gases created by ignition of a cartridge without necessarily retarding the passage of the bullet through the gun barrel. In certain of the prior art designs, the noise suppressor is designed to effect rapid cooling of exhausting gases and the reduction of pressure therefrom before the gases emerge from the end of the noise suppressor device. Typically, the well-known noise suppressors have a large cross-sectional area providing a chamber through which a bullet passes that contains heat absorbing and/or exhaust gas-defusing materials.
Although most noise suppressors are large diameter cylindrical devices that are screwed onto the end of a firearm barrel, it is also known to provide a noise suppressor or silencer along the entire length of an enlarged-diameter rifle barrel.
While there have been a number of advances in art of firearms suppressors, there continues to be a need for improvement. For example, many of the present suppressor designs are large and bulky, making them awkward to handle, especially in tight quarters. Some have wearable components such as baffles and O-rings which wear over time. Many of the present designs fail to offer a self-cleaning feature.
The method of the present invention is directed toward increasing the shooting accuracy achievable with rifles, and particularly when shooting a rifle at a given, fixed distance using ammunition of varying velocity, or under varying atmospheric conditions. By this means, it becomes possible to “match” the rifle to a particular ammunition. Thus, it is unnecessary to select a cartridge based upon the inherent responses of a particular rifle or the necessity of having the rifle barrel matched to a particular brand and/or velocity of ammunition. Accordingly, factory loaded ammunition can be shot at even very great distances with accuracies heretofore unobtainable. Moreover, different factory loaded cartridges can be fired accurately from the same rifle by merely making appropriate system adjustments.
The method of the invention thus provides a method of increasing rifle accuracy by converging bullet velocity to a given distance. To accomplish this purpose, a rifle is first provided with a stock having a butt section and a forearm section with a stock recess, an action/receiver with a front face and a rear face, a vertically depending recoil lug attached to the front face of the action and a one piece barrel having a barrel shoulder at one end which extends outwardly from the recoil lug and which has a distal, muzzle end. The barrel is mounted in free-floating fashion within the stock recess so that the barrel extends from the recoil lug and rifle action and so that nothing is touching between the stock and the barrel forward of the recoil lug. The rifle action is extended with a tensioning bar which is welded to the recoil lug, the tensioning bar extending in a generally horizontal plane outwardly from the recoil lug in the direction of the barrel. The rifle is also provided with an adjustment knob which extends vertically downward from the rifle forearm at one extent and which contacts the tensioning bar at an opposite extent. The adjustment knob can be adjusted between minimum and maximum positions, the maximum position serving to restrict the tendency of the action to lift up out of the stock recess under recoil.
The barrel is designed with certain specified characteristics. The barrel has a solid bull muzzle end with a recessed crown, the barrel weight which exists in front of the recessed crown being in tune for one specific distance only. Preferably, the barrel is cut to a specific length and muzzle weighted to tune the barrel to the longest expected shooting distance which is expected to be encountered. The barrel has a narrowed mid-section which produces an increased, “whippy” vertical bending action under recoil and a thus a wider tune spectrum on the vertical upswing of the barrel under recoil.
The tensioning bar and adjustment knob are incrementally adjusted to vary any muzzle weighted effect produced by the barrel design when shooting at shorter distances or when there is a velocity variance in the ammunition being used in the rifle. In a preferred embodiment of the invention, adjusting the tension on the tensioning bar with the adjustment knob between minimum and maximum positions acts to restrict movement of the action and, in turn, upward force on the barrel acting to lift the barrel upward from the stock recess, thereby reducing vertical whipping action of the barrel at shorter shooting distances or to compensate for variances in ammunition velocity. The barrel design, along with the tensioning bar and adjustment knob provide infinite tuning accuracy with varying velocity ammunition and in varying atmospheric conditions.
A novel noise suppressor design is also shown. The noise suppressor can be used with the previously described, highly accurate rifle, or with other rifle designs where the rifle has a barrel at a breach end, the barrel also having an externally threaded, distal end. The noise compressor has an inner core component and an outer sleeve component, the outer sleeve component being closely received about the inner core component in use. The inner core component is a one piece design, preferably formed of a single piece of metal.
The inner core component has an internally threaded, barrel receiving end which receives and engages the exteriorly threaded end of the rifle barrel in overlapping fashion, an oppositely arranged exteriorly threaded end, and a central bore between the two ends which allows the passage of a bullet when the bullet is fired, firing of the bullet also setting off hot exhaust gases in the central bore. The sleeve component forms a surrounding outer chamber between the sleeve component and the inner core component when in place on the inner core component. The inner core component also has an inner chamber with at least one pair of oppositely facing window openings for exhausting gases from the inner chamber into the surrounding outer chamber. The inner core component also has an exterior longitudinal region forward of the central chamber, the exterior region having a series of longitudinally aligned, upwardly extending teeth formed therein for reducing the velocity of the hot gases contacting the upwardly extending teeth.
Preferably, the longitudinally aligned teeth on the longitudinal region of the suppressor define a series of teeth crests separated by a series of troughs and the rests of the longitudinally aligned teeth are inclined slightly in the direction of the central chamber and the direction of the hot gases being exhausted therein.
In the preferred design, the central chamber has a rearward bore region which extends in the direction of a corresponding bore region in the rifle barrel, so that a bullet exiting the rifle barrel at least partly enters the rearward bore region before completely exiting the rifle bore region. The central chamber, in addition to the pair of oppositely arranged window openings, also preferably has a pair of top and bottom openings for exhausting additional gases from the central chamber.
The internally threaded, barrel receiving end of the inner core component which receives and engages the exteriorly threaded end of the rifle, together with the oppositely arranged exteriorly threaded end, together provide a two-point mount for the noise suppressor on the rifle barrel. A threaded cap is preferably provided which engages the exteriorly threaded end of the inner core component to complete the two-point mount. In one preferred form of the invention, the threaded end cap has an internal bevel which matches the contour of an external bevel provided on outer sleeve when the threaded end cap is engaged with the exteriorly threaded end of the inner core component.
When the noise suppressor of the invention is used with the highly accurate rifle design of the invention, the noise suppressor adds weight forward of the crown of the rifle muzzle, the added weight being proportional to a desired tuning effect at a longest expected shooting distance, for positively compensating the rifle for slower bullet velocities.
Additional objects, features and advantages will be apparent in the written description which follows.
The preferred version of the invention presented in the following written description and the various features and advantageous details thereof are explained more fully with reference to the non-limiting examples included in the accompanying drawings and as detailed in the description which follows. Descriptions of well-known components and processes and manufacturing techniques are omitted so as to not unnecessarily obscure the principle features of the invention as described herein. The examples used in the description which follows are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those skilled in the art to practice the invention. Accordingly, the examples should not be construed as limiting the scope of the claimed invention.
Rifle Accuracy System:
In a first aspect, the present invention deals with a rifle accuracy system which will now be described. Turning to
The concept of “positive compensation” is based on the fact that when any given batch or type of ammunition is chronographed, there is a always a spread in muzzle velocity observed about a mean. As a consequence, there will be a vertical dispersion in the fall of shot at the target due to the fact that the slower bullets in the sample take longer to travel down the range and so drop further than the faster bullets. The expected vertical dispersion can be calculated for a given batch of ammunition due to the observed spread in muzzle velocity.
However, it is often observed that the calculated vertical dispersion is not evident on the target, at least at certain distances The concept of “positive compensation” can be used to explain this result. It is generally recognized that the shock of the recoil forces in the rifle generate up and down vibrations in the barrel. For positive compensation, it is envisaged that the bullet is exiting the muzzle during an upward swing in the vibration at the muzzle, such that faster bullets (which arrive at the muzzle slightly earlier than slow bullets) are launched at a slightly lower angle into their trajectory than slower bullets. This will tend to reduce the vertical dispersion in the group at the target resulting from the variation in muzzle velocity. If the upward swing in the muzzle is exactly right, there will be complete positive compensation as the trajectories of bullets across the entire spread of muzzle velocities all meet at the same height on the target at a given range
Returning now to the description of the rifle of the invention,
As has been briefly described, when the rifle 11 is fired, the exiting bullet exerts an opposite, recoil force on the rifle action which is transmitted through the stock to the shooter's shoulder. The center of gravity of the rifle action is lower than the central axis of the rifle barrel. Thus, the force of recoil tends to act to lift the action upwardly from the stock. At the same time, the muzzle end of the barrel begins an upswing motion relative to its rest position. As previously mentioned, when shooting targets at a given distance, a slower velocity bullet will tend to exit the muzzle of the rifle when the rifle barrel is at a point further along on the upswing path of travel than would a faster velocity bullet. As a result, the slower bullet tends to strike the target at a higher relative position than a higher velocity bullet for a certain given distance.
The present invention has as its object to compensate for these variations in bullet velocity at a given distance, and also for the effects of atmospheric conditions such as temperature. However, it goes about this differently than the techniques popularized in the current state of the art. Instead of attempting to control “barrel harmonics” or vibrations, as with a sliding weight, Applicant intentionally provides a rifle design with a barrel having “whippy” recoil characteristics. These characteristics would be just the opposite of the designer of a rifle having some sort of harmonic vibration compensating mechanism. By harmonic vibration compensating mechanism, Applicant would refer the reader to the Browning BOSS® system described in RE 35,381 as discussed in Applicant's Background description.
In Applicant's design, the barrel 29 is mounted in “free-floating” fashion within the stock recess 19 so that the barrel extends from the recoil lug 27 and rifle action 21 and so that nothing touches between the stock and the barrel forward of the recoil lug (see
Bedding increases accuracy in part by relieving stress on the action. The rifle's action will rarely sit flush in the stock without bedding. This causes the action to flex when tightening the bolts holding the action to the stock. The flexing results in a loss of accuracy. Bedding will create a flush surface for the action and prevent flexing. Bedding also reduces movement of the action in the stock. Without bedding, the action may be more likely to shift after a shot. If the action shifts and does not return to same spot in the stock the rifle will lose the ability to maintain zero. Full contact bedding of the action, with the barrel floated, is thus a knoown method for long range rifles with a heavy barrel. A free-floating barrel will generally produce the greatest accuracy. In the case of the rifle of the invention, the rifle barrel thus floats within the stock recess and extends from the action/receiver.
With the bedding so positioned, it functions as a shock absorber. The actual bedding material can be chosen from a number of shock absorbing or stabilizing materials. For example, it may be a synthetic rubber or similarly resilient elastomeric material.
In the case of the Applicant's design, the barrel is a solid, one piece barrel which is cut to a specific length and muzzle weighted to tune the barrel to the longest expected shooting distance. For example, the barrel might be “tuned” to shoot groups at 1000 yards in bench rest competition. The desired “tuned” characteristics are achieved by providing the rifle with a barrel having a solid “bull”, (enlarged) muzzle end 33 (
The amount of weight needed in the front (crown) region of the rifle barrel can be determined empirically by shooting at a given distance and gradually adding weight to the barrel until the bullets are hitting the same spot on the target. A different weight will be required for a different caliber rifle. For example, 5 ounces for a 6 mm Remington™, 10 ounces for a 7 mm and 11 ounces for a 30 caliber. A rimfire, being about a three times slower bullet, will require something on the order of 16 ounces of added weight forward of the barrel crown.
Perhaps surprisingly, every gun converges at one spot only. This is illustrated, in simplified fashion, in
Note the convergence at 5 ounces of weight in front of the recessed crown of the barrel. Every gun converges at 5, 10, 16, 24, etc. ounces, but there is only one point in which the slower round hits the target higher than the faster round, showing over (positive) compensation at 100 yards. This means that the bullets will necessarily converge at a longer distance. The reversion in the point of impact (POI) usually happens shortly after one of the convergence points of weighting, as is illustrated somewhat schematically in Chart I above.
With this barrel design and proper weighting, it is possible for Applicant to “tune” the barrel to hit a “sweet spot” at a given, fixed distance. The “sweet spot” is achieved when the barrel design produces shot groups at which the trajectories of a series of bullets discharged from the muzzle of the rifle held in a stationary position exhibit a minimum deviation at the given, fixed distance. This would be for 5 ounces of added weight for the 6 mm Remington™ rifle discussed above.
Applicant's inventive method also provides a technique for decreasing the “positive compensation” achieved by the barrel design to compensate for varying velocity ammunition or for shooting at shorter distances than the design distance of the barrel. This is accomplished, in part, by extending the rifle action with a tensioning bar (39 in
Tension on the tensioning bar is adjusted by providing an adjustment knob 43 which extends vertically downward from the rifle forearm at one extent and which contacts the tensioning bar at an opposite extent. In the example illustrated, the adjustment knob is a simple screw mechanism received within a threaded bore in the stock forearm. A spring can also be placed between the length of the threaded screw and the tensioning bar to provide a finer degree of tuning. Turning the adjustment knob inwardly exerts a force on the tensioning bar, thereby restricting the tendency of the action to lift up out of the stock recess under recoil. In this way, the tensioning bar 39 and adjustment knob 43 can be used to control the vertical bending and upswing of the rifle barrel under recoil so as to converge velocity to a given fixed distance.
In other words, adjusting the tension on the tensioning bar with the adjustment knob acts to restrict movement of the action/receiver and, in turn, upward force on the barrel acting to lift the barrel upward from the stock recess, thereby reducing the vertical whipping action of the barrel at shorter shooting distances or to compensate for variances in ammunition velocity. In this way, ammunition with varying velocities will hit the same “sweet spot” on a target at the given fixed distance. The tensioning bar and adjustment knob can be incrementally adjusted to vary any muzzle weighted effect produced by the barrel design when shooting at shorter distances or when there is a velocity variance in the ammunition being used in the rifle.
The Noise Suppressor System:
The noise suppressor system of the invention will now be described. Although the noise suppressor (shown at 51 in
With reference to
The inner core component also has an oppositely arranged exteriorly threaded end 65. A central bore 67 extends between the two ends of the core component and is aligned in use to a high degree of accuracy with the center bore of the rifle barrel at all times. As will understood by those skilled in the relevant shooting arts, firing of a bullet though the rifle barrel sets off hot exhaust gases in the central bore 67.
The sleeve component 57 forms a surrounding outer chamber between the sleeve component 57 and the inner core component 55 when the sleeve is in place on the inner core component. The chamber would generally exist along the length of the outer diameter of the inner core component between the lug region 61 and the threaded end 65. As can be seen in
As best seen in
It will also be appreciated from
This “deep hole” technology can help to stabilize a balloting or wobbling bullet as it exits the rifle muzzle and passes on to the continuation bore 88. The flow of hot gases around the bullet in the central chamber causes an effect which may be analogized to that of a “venturi” effect which straightens the bullet path out. This feature eliminates the need for specific bullet seating depth calculations intended to compensate for variations in bullet seating depth due to the throat melting forward in normal use.
The internally threaded, barrel receiving end of the inner core component 55, which receives and engages the exteriorly threaded end of the rifle, together with the oppositely arranged exteriorly threaded end 65, together provide a “two-point mount” for the noise suppressor on the rifle barrel. This is accomplished by the engagement of the core component internally threaded end with the exterior threads 53 of the rifle barrel at one extent and by the engagement of a threaded end cap (87 in
As shown in
The particular arrangement of the internal and external chambers of the noise suppressor, together with the window openings and specially profiled outer longitudinal surface surprisingly create a self-cleaning design. While not wishing to be held to any particular theory, the presence of the teeth or facets on the outer longitudinal surface of the inner core component, rather than using round discs, is thought to play an important role in achieving the cleaning effect. The gas velocity is being increased within the “can” defined by the inner core component and outer sleeve. The teeth or fins divert high speed air which further increases the velocity. By its nature, the suppressor reduces air pressure by its internal volume while the velocity is kept high for the cleaning effect.
While the noise suppressor of the invention could be used with various rifle designs, it can also advantageously be used with the highly accurate rifle design previously described. In other words, the noise suppressor adds weight forward of the crown of the rifle muzzle, the added weight being proportional to a desired tuning effect at a longest expected shooting distance, for positively compensating the rifle for slower bullet velocities. The effect of the added weight forward of the barrel crown would be the same as has previously described with respect to
An invention has been provided with several advantages. The rifle design of the invention intentionally creates more rifle bending with the bending then being controlled by restricting the specific weight in front of the crown with a particular type of adjustment mechanism. The barrel being tuned for one distance only. Applicant's design intentionally creates a large positive compensation due to the barrel contour and weighting with an exaggerated “whippy” vertical bending under recoil. The result is a wider tune spectrum upon upswing of the barrel as compared to systems which are tying to “dampen” vibrations in the rifle barrel. The stock tension device, in simple terms, acts as a sort of switch to turn the muzzle weighted effect off or partially off by incremental movement of the adjustment knob. Once the rifle is calibrated, if a velocity variance in ammunition is detected, the convergence point of the bullet can be adjusted. The barrel is cut and weighted for the longest expected shooting distance with the tensioning adjustment being used for adjustments when shooting shorter distances or in varying atmospheric conditions.
The noise suppressor of the invention can be used with the highly accurate rifle design described, or with other rifle designs. The suppressor overlaps the threaded rifle barrel and is engaged by a two-point mount. The suppressor proportions weight in front of the barrel crown for tuning. The specially designed chambers and windows allow gases in the central chamber to pass around the inner core component, allowing gases to flow forward and backward. The design helps to eliminate turbulence in the bullet's flight path. The flow of the high velocity gases in the central chamber helps to stabilize a yawing bullet resulting from bore yaw. The teeth or facets on the exterior surface of the inner core component are self-cleaning. The design eliminates the need for O-rings or internal baffles which can wear with use. The one-piece design is sturdy and strong.
While the invention has been shown in only two of its forms, it is not thus limited and is susceptible to various changes and modifications without departing from the spirit thereof.
The present application claims priority from a previously filed provisional application, Ser. No. 61/862,288, filed Aug. 5, 2013, entitled “Method of Improving Rifle Accuracy”, by the same inventor.
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Number | Date | Country | |
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20150267988 A1 | Sep 2015 | US |
Number | Date | Country | |
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61862288 | Aug 2013 | US |