Patent Application
20090223103
1. The Field of the Invention
The present application generally relates to firearms and magazines for firearms. In particular this application discusses magazines.
2. The Relevant Technology
Modern firearms make use of cartridges that include a projectile seated in a casing. The casing has an internal cavity defined therein that contains a charge of rapidly combusting powder. A primer is seated in a recess formed in a rear portion of the casing. A hole in the primer casing places the primer in communication with the internal cavity containing the powder. A projectile is seated in the front portion of the casing such that the powder is more or less sealingly contained in the casing between the primer and the projectile.
An action, such as a bolt action, is used to advance the cartridge into a firing chamber ahead of firing. While in the firing chamber, a firing pin strikes the primer, causing the primer to ignite. The ignition is directed to the powder, which burns within the casing. The powder burns within the casing generates a rapidly expanding gas. The pressure generated by the rapidly expanding gas propels the projectile from the casing and through the barrel of the firearm. The action can then be cycled to remove the empty casing. Cycling the action includes withdrawing the action from the firing chamber to extract a cartridge, and then advancing the action to position another cartridge within the firing chamber.
Often a magazine holds additional cartridges such that as the cartridge is advanced toward the firing chamber, an additional cartridge is automatically fed into the firing chamber. Such a configuration can allow for relatively rapid feeding of cartridges. A feed rate can be further enhanced through the use of a detachable magazine, some times referred to as a clip. The clip often includes a body that is sized to receive several cartridges. A spring and follower are positioned within the body that maintain the top cartridge in such a position that when the clip is attached to the firearm advancing the action feeds a cartridge into the firing chamber as discussed above.
The range and accuracy with which a firearm shoots the projectile can depend on a number of factors. Accuracy is often measured by the area over which projectiles impact a target. Factors that affect accuracy can include, among others, variable forces on the barrel, variations of the position of cartridges relative to the firing chamber and/or relative to the barrel, variations in the powder charge, the seating force between the projectile and the casing, and the orientation and position of the projectile relative to the casing. To maximize range, relatively large charges of powder are used to propel relatively heavy projectiles.
In order to maximize accuracy, especially with cartridges for long range shooting, variation is minimized from cartridge to cartridge and from shot to shot. One approach is to use cartridges loaded in a carefully controlled manner. By reducing variation and using large powder charges and heavy projectiles, accurate shots of more than 1,000 yards are possible. While providing for accuracy at long ranges, the recoil associated with large powder charges and heavy projectiles generates significant recoil can be significant.
Often, the recoil can be sufficiently violent to cause the front of the magazine to impact the tip of any projectiles in the magazine. Accordingly, to ensure accuracy at long ranges, cartridges are single fed into the firing chamber instead of using a magazine. While such an approach can eliminate contact between a cartridge and the magazine, and thus eliminate impact of the magazine with the tip of the projections, single feeding cartridges can increase the possibility that the shooter will drop a cartridge and thereby negate many of the processes used to maintain consistency. Further, single feeding can be time consuming and tedious.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some examples described herein may be practiced.
A magazine configured to receive a plurality of cartridges includes a front portion, a rear portion, and opposing lateral portions between the front portion and the rear portion, the opposing lateral portions including a neck portion, a shoulder portion adjacent the neck portion, and a base portion adjacent the shoulder portion, wherein a width of the neck portion adjacent the shoulder portion has a width that is about 0.005 inches to about 0.04 inches or more greater than the nominal size of a neck portion of the cartridges.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential characteristics of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Together with the following description, the Figures demonstrate and explain the principles of a magazine configured to reduce jamming and/or protect a tip of a projectile. In the Figures, the thickness and configuration of components may be exaggerated for clarity. The same reference numerals in different Figures represent similar, though necessarily identical, components.
Magazines, firearms, and methods of manufacture are provided herein that allow multiple cartridges to be loaded into a magazine. The magazines include a front wall, a rear wall, and opposing lateral portions between the front wall and the rear wall. The lateral portions include a neck portion adjacent the front wall that is configured interact with cartridges to prevent a tip of the cartridge from impacting the front wall as the firearm to which the magazine is attached recoils. For example, a relatively small clearance can be provided between a neck portion of the magazine and a corresponding neck portion of a casing. The relatively small clearance can help retain a shoulder portion of the casing during recoil to help prevent the shoulder of the casing from jamming in the neck portion of the magazine. Accordingly, the magazine can include a shoulder retention feature. Such a configuration can allow successive cartridges to fed from the magazine while maintaining the interface between the cartridge's casing and projectile, thereby maintaining consistency. Accordingly, such a configuration can allow for relatively rapid shots while maintaining accuracy.
Regardless of the type, cycling of the action 115 moves a cartridge into position to be fired and removes the casing after the cartridge has been fired. For example, forward operation of the action 115 can move a cartridge through a breech 125 and into position with the barrel 115. Thereafter, a trigger (not shown) can be actuated to release a firing pin in the action 115. The firing pin strikes a primer, which ignites gun powder in a casing to propel a projectile through the barrel 110.
Rearward operation of the action extracts the spent casing and moves the action 115 rearward of the magazine 120. The magazine 120 is coupled to the stock 105 and is operatively associated with the action 120 and/or the breech 125 in such a manner that forward operation of the action moves a cartridge from the magazine 120 into position with the barrel 115. The process can then be repeated until the rounds in the magazine 120 are complete.
Thereafter, additional cartridges can be fed into the magazine 120. In one example, cartridges can be fed through the breech 125 into the magazine 120. In other examples, the magazine 120 can be a detachable magazine. In such a configuration, cartridges can be fed either through the breech 125 or the magazine 120 that can be detached from the stock 105. For ease of reference, a detachable magazine will be described below. It will be appreciated that a permanently secured magazine can also be described.
In particular, as illustrated in
In addition to defining a profile corresponding to the profile of the cartridge 230, the lateral portions 210 define a cavity configured to receive the cartridge 230. As illustrated in
In order to load cartridges 230 into the detachable magazine 200, the base portion 245B of a casing 235 is positioned under the lips 260, 265 in opposition to a biasing force exerted on the casing 230 by the follower and biasing member described above. The casing 235 can then be moved rearward and downward to the loaded position shown in
As previously introduced, when cartridges 230 are loaded into the detachable magazine 200, the neck portion 245B, the shoulder portion 250B, and the base portion 255B are in proximity with the neck portion 245A, the shoulder portion 250A, and the base portion 255A of the detachable magazine 200. Such a configuration allows the detachable magazine 200 to retain the shoulder portion 250B of the casing 235 to help reduce impact between the front portion 205 of the detachable magazine 200 and/or help ensure proper feeding of the cartridge 230.
For example, while a cartridge 230 is in one of the second positions, a space between tips of projectiles 240 and the front portion 205 of the detachable magazine 200 can help ensure that relative movement between the cartridge 230 and the detachable magazine 200, such as can occur during recoil, does not result in contact between the projectile 240 and the front portion 205. For example, the shoulder portion 250A of the detachable magazine 200 can interact with the shoulder portion 240B of the casing 235.
In particular, an internal width of the neck portion 245A of the detachable magazine 200 corresponds closely to the nominal size of the neck portion 245B of a type of cartridge 230 to be used with the detachable magazine. For example, the neck portion 245A can have a width that is approximately 0.005 inches to about 0.04 inches or more greater than the nominal size of the neck portion 245B of the casing 235. Further, such a width can have a range that is approximately 0.01 inches to about 0.025 inches. Accordingly, in the case of a detachable magazine configured for use with .338 Lapua Magnum cartridges with a nominal diameter of 0.372 inches, a neck portion can have a width of between about 0.377 inches to about 0.412 inches, such as a width of between about 0.382 inches to about 0.397 inches. Such clearances can be optimized for a magazine formed from rolled and stamped steel. A relatively larger clearance, such as a clearance of greater than 0.04 inches to about 0.06 inches or more can be provided so long as the clearance retains the shoulder portion of the casing and prevents the shoulder portion from jamming into the neck portion of the magazine. Accordingly, in some examples clearance between a neck portion of the magazine adjacent the shoulder portion of the magazine can be selected according the material used to form the detachable magazine to thereby reduce or eliminate the potential for a shoulder portion of a casing to become jammed in the neck portion of a magazine.
Similarly, in the case of a detachable magazine configured for use with .300 Winchester Magnum cartridges with a nominal diameter of 0.339 inches, a neck portion can have a width of approximately 0.344 inches to about 0.379 inches, such as a width of between about 0.349 inches and about 0.364 inches. A detachable magazine configured for use with .308 Winchester cartridges with a nominal case neck diameter of 0.343 inches can have a width of approximately 0.348 inches to about 0.383 inches, such as a width of between about 0.353 inches and about 0.368 inches. Further, it will be appreciated that detachable cartridges can be configured for use with any type of cartridge as desired.
It has been found that maintaining the width of neck portions within this range can help reduce the possibility that cartridges will slip forward in response to forces, such as recoil. Preventing cartridges from slipping forward can reduce or eliminate contact between the projectile 240 and the front portion 205 of the detachable magazine 200 as well as reducing the likelihood that the shoulder portion 250B of the casing 235 can become wedged into the shoulder portion 250A of the detachable magazine 200 thereby reducing the likelihood of miss-feeds and thus providing shoulder retention.
The neck portion 245A of the detachable magazine 200 can have the width described above for any desired length within the detachable magazine, including the entire height, a partial height, or any other combination of heights. Accordingly, the detachable magazine 200 is configured to carry several cartridges in such a manner as to reduce or eliminate contact between a cartridge's projectile and a front portion of the detachable magazine while preventing the cartridge from being wedged into some portion of the detachable magazine. While a cartridge or cartridges 230 are thus loaded in the detachable magazine 230, the lips 260, 265 cooperate with the follower and biasing member to maintain a cartridge 230 in position to be fed into position in the barrel by an action. The lips 260, 265 can be positioned and oriented such that part of the base portion 245B of the casing 235 extends above the rear portion 220 of the detachable magazine while a cartridge 230 is in the first position described above.
Placing the base portion 245B of the casing 235 in this position allows an action to engage a cartridge 230 in the first position and cycle the cartridge forward to be fired. As shown in
As the cartridge 230 is cycled forward, the biasing member moves the follower described above toward the lips 260, 265. If a cartridge is in a second position, the follower moves the cartridge into the first position. A spent casing is extracted and ejected by the action as it cycles rearwardly, thereby placing the action in position to load another cartridge, thus repeating the cycle.
Accordingly, a plurality of cartridges can be loaded into a detachable magazine with shoulder retention features. The detachable magazine can securely retain the cartridges and help reduce or eliminate impact between a projectile and the front portion of the detachable magazine due to recoil or other forces. The size of the neck portion can be selected to help reduce or eliminate the potential for the neck portion of cartridges from becoming wedged into the corresponding neck portion of the detachable magazine.
In the illustrated example, one or more of the lateral portions 210, 215 includes a recess 270 defined therein for receiving a magazine release mechanism associated with a stock. Accordingly, the detachable magazine 200 can be released by selective engagement with the recess 270 and a corresponding tab of a magazine release mechanism. While a detachable magazine is shown, it will be appreciated that any type of magazine can be configured as described above. Such magazine types can include fixed, semi-fixed, or any other type of magazine. Further, while operation of the magazines has been described with reference to a bolt-action firearm, it will be appreciated that a magazine configured as described above can be used with any type of action.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application is a continuation-in-part application of U.S. patent application Ser. No. 12/190,401 filed Aug. 12, 2008 and entitled “Firearm Stock Features,” which is a utility of U.S. Provisional Patent Application Ser. No. 61/025,242 filed Jan. 31, 2008, which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61025242 | Jan 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12190401 | Aug 2008 | US |
| Child | 12464573 | US |
