This invention relates to ammunition magazines, and in particular, magazines for push-feed firearms.
During operation of a so-called “push-feed firearm” an ammunition cartridge is substantially unguided in its travel between the magazine and the chamber after leaving the magazine's feed lips which otherwise retain the cartridges within the magazine. Push-feed firearms contrast with controlled-feed firearms in that during operation of a controlled-feed firearm the cartridge is held first by the magazine feed lips and then held by the extractor as the cartridge is chambered, thereby ensuring proper and reliable ammunition feed during cycling of the firearm action.
The substantially unguided nature of ammunition feed in the push-feed firearm allows a cartridge to be pushed laterally out of alignment with the bolt and chamber by cartridges following the cartridge being chambered as well as by the magazine follower when the cartridge is the last round in the magazine. This effect can be particularly troublesome in prior art rotary magazines 10, as shown in
Prior art push-feed magazines are also prone to other failure modes. For example, a cartridge can simply drop from the action on its way into the chamber if the rifle is held on its side with the ejection port down. There is clearly an opportunity for improvement in magazines for push-feed firearms.
The invention concerns a magazine for a firearm for holding a plurality of ammunition cartridges. In one example embodiment the magazine comprises a plurality of sidewalls defining a space for holding the cartridges. An opening is defined between a first and a second of the sidewalls providing access to the space. A spring-biased follower is positioned within the space for urging the cartridges held within the space toward the opening. In this example, first and second feed lips are positioned on the first and second sidewalls on opposite sides of the opening. The feed lips project toward one another so as to contact and retain at least one of the cartridges within the space. The feed lips extend lengthwise along a first portion of the opening. A first guide surface is positioned on the first sidewall adjacent to the first feed lip. The first guide surface extends lengthwise along a second portion of the opening and projects away from the space so as to guide the cartridges once disengaged from the feed lips.
In one example embodiment, the first guide surface is contiguous with the first feed lip. In a particular example embodiment, the first guide surface comprises a continuous surface. A specific example embodiment further comprises first and second feed ramp surfaces positioned on opposite sides of the opening. The first and second feed ramp surfaces are angularly oriented with respect to the first and second feed lips. The first feed ramp surface is positioned on the first sidewall, and the second feed ramp surface is positioned on the second sidewall. The first guide surface is positioned between the first feed lip and the first feed ramp surface.
In an example embodiment the first guide surface is contiguous with the first feed ramp surface. Another example embodiment comprises a second guide surface positioned on the second sidewall adjacent to the second feed lip. The second guide surface extends lengthwise along the second portion of the opening and projects away from the space so as to guide the cartridges once disengaged from the feed lips. In a specific example embodiment the second guide surface is contiguous with the second feed lip. In another example embodiment the second guide surface comprises a continuous surface.
By way again of example, the magazine according to the invention further comprises first and second feed ramp surfaces positioned on opposite sides of the opening. The first and second feed ramp surfaces are angularly oriented with respect to the first and second feed lips. The first feed ramp surface is positioned on the first sidewall, and the second feed ramp surface positioned on the second sidewall. In this example the first guide surface is positioned between the first feed lip and the first feed ramp surface, and the second guide surface is positioned between the second feed lip and the second feed ramp surface.
In another example embodiment the first guide surface is contiguous with the first feed ramp surface. By way of further example, the second guide surface is contiguous with the second feed ramp surface.
In a particular example embodiment, the follower comprises a paddle rotatable about an axis aligned lengthwise along the opening.
The invention further encompasses a magazine for a firearm for holding a plurality of ammunition cartridges. In this further example embodiment the magazine comprises a plurality of sidewalls defining a space for holding the cartridges. An opening is defined between a first and a second of the sidewalls providing access to the space. A spring-biased follower is positioned within the space for urging the cartridges held within the space toward the opening. First and second feed lips are positioned on the first and second sidewalls on opposite sides of the opening. The feed lips project toward one another so as to contact and retain at least one of the cartridges within the space. The feed lips extend lengthwise along a first portion of the opening. First and second guide surfaces are positioned respectively on the first and second sidewalls adjacent to the first and second feed lips. The first and second guide surfaces extend lengthwise along a second portion of the opening and projecting away from the space so as to guide the cartridges once disengaged from the feed lips.
An example embodiment of the magazine further comprises first and second feed ramp surfaces positioned on opposite sides of the opening. The first and second feed ramp surfaces are angularly oriented with respect to the first and second feed lips. The first feed ramp surface is positioned on the first sidewall, and the second feed ramp surface positioned on the second sidewall. The first guide surface is positioned between the first feed lip and the first feed ramp surface, and the second guide surface is positioned between the second feed lip and the second feed ramp surface.
In a specific example embodiment, the follower comprises a paddle rotatable about an axis aligned lengthwise along the opening.
In a specific example embodiment the first guide surface is contiguous with the first feed lip. Further by way of example, the second guide surface is contiguous with the second feed lip. In a particular example embodiment the first guide surface comprises a continuous surface. In another example, the second guide surface comprises a continuous surface. By way of further example, the first guide surface is contiguous with the first feed ramp surface. Again by way of example, the second guide surface is contiguous with the second feed ramp surface.
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This application is a non-provisional of and claims benefit of priority to U.S. Provisional Patent Application No. 62/073,219, filed Oct. 31, 2014, which provisional application is hereby incorporated by reference herein.
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Number | Date | Country | |
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62073219 | Oct 2014 | US |