Chamber Nested Bolt and Oval Rifling

Abstract

A means of keeping the cartridge in the chamber during the firing sequence until the peak pressure drops to a safe level by nesting the bolt into the chamber with the cartridge. The bolt and cartridge will form a gas seal and recoil backwards when the gun is fired, but the chamber walls will support the cartridge while it recoils backwards until it exits. The gun will be designed so that it does not exit until the pressure drops to a level where the cartridge can withstand the force. Doing this will allow the gun to utilize high pressure ammunition without requiring complicated locking and / or delay mechanisms currently used. This will decrease the initial cost of manufacturing the gun, improve accuracy and reliability, and reduce the peak recoil felt from the gun. Also spinning a projectile by using an oval cross section where the major and minor axis rotates around the center of the oval eliminates the need for groves and polygonal rifling. This will increase the efficiency and the precision of the gun.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefits of provisional patent application No. 62 / 674,015 filed 2018 May 20 by the present inventor.FEDERALLY SPONSORED RESEARCH[0002]Not ApplicableSEQUENCE LISTING OR PROGRAM[0003]Not ApplicableBACKGROUNDField[0004]This application relates to a novel recoil operated system that simplifies the construction of guns while improving their accuracy and reliability and improving the accuracy of the barrel by utilizing a oval barrel cross section that rotates around its major and minor axis to to cause the projectile to spin.Prior Art[0005]For the remainder of this patent, a gun refers to any tube from which bullets, shells, or other missiles can be propelled by gas pressure. The gasses can be generated with a high pressured tanks, chemical reactions, or other methods. Simple blowback guns are less expensive to manufacture and more reliable, but can not currently be used with guns designed to shoot high pressured amm...

AI Technical Summary

Benefits of technology

This patent describes guns that use a bolt that is nested inside the chamber of the gun before firing and utilizes an oval cross section where the major and minor axis rotate about the center to replace traditional rifling. This allows the gun to use ammunition that operates at higher pressures than traditional guns without added complexity. The oval shape of the projectile also reduces distortion and friction inside the barrel, resulting in a higher muzzle velocity and longer barrel life. The gradual transition from the circular chamber cross section to the oval barrel cross section also increases consistency of the projectiles and allows for the use of delicate projectiles. The firearm can also incorporate additional means of controlling the speed of the bolt's recoil.

Problems solved by technology

Simple blowback guns are less expensive to manufacture and more reliable, but can not currently be used with guns designed to shoot high pressured ammunition or large projectiles.

The alternative to using simple blowback guns is using gas operated cycles or delayed blowback mechanisms, but this complicates the design of the gun.

The increase in complexity increases the cost to manufacture the gun, the likelihood that the gun malfunctions, and, in some cases, can decreases the accuracy of the gun.

This design is theoretically wonderful, but it is difficult to implement.

One problems is that the bolt must be designed around a specific type of ammunition, limiting the flexibility of the gun.

The main drawback, however, is the timing of the ignition of the projectile.

Very slight differences in ignition will cause different recoil, resulting in poor grouping.

This design also does not anticipate hangfire (where the projectile experiences a delay between when the trigger is pulled and when the propellant ignites).

When this occurs, open bolt guns reverts to a simply blow back system with an inadequate slide mass and spring force creating a dangerous situation for the shooter, and the possibility that the gun is damaged.

Due to the challenges presented with timing, the open bolt design is only currently used with low pressure ammunition in sub machine guns such as the Uzi.

After the War, the US Army determined it was not a suitable design.

While the spin is invaluable for stabilizing the projectile, the act of cutting the projectile with the lands causes numerous problems with interior and exterior ballistics.

The lands are slowly worn away by the projectile, causing the barrel to lose accuracy over time.

Additionally, creating a seal between the lands and groves is difficult which allows gas to leak out.

The lands also rapidly deform the projectiles, resulting in copper or lead build up and creating tremendous amounts of friction inside the barrel.

This friction causes the projectile to have a lower velocity, and causes the barrel to distort decreasing the accuracy and power of the gun.

The deceleration causes a decrease in energy in the projectile and an increase in flight time.

The increase in flight time increases the deviation caused by the wind and causes a larger projectile drop.

This introduces a gyroscopic drift (also known as spin drift), which causes a larger circular error probability.

The primary challenge of polygonal rifling is creating an effective seal and eliminating fouling inside of the barrel.

It is difficult to create a seal with polygonal rifling due to the non circular cross section of the shape.

Fouling is also an issue due to the difficulty of creating a smooth transition from a circular cross section in the chamber to a polygonal cross section in the barrel.

The decrease in friction inside the barrel will result in a higher muzzle velocity and a longer barrel life.

The decrease in projectile deformation will also decrease the projectile's air resistance once it exits the barrel.

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