Firearm Throat Design with Segmented Rifling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Firearm barrels with short throats and single tapered steps experience high chamber pressure and bullet misalignment, limiting muzzle velocity and accuracy due to uniform depth rifling grooves.
Innovation Solution
A firearm throat design featuring a cylindrical elongated body with straight side walls, a first beveled step between the free bore and the elongated body, and a second beveled step communicating with the rifle bore, incorporating continuous and gradually increasing rifling grooves and lands that start in the first step and extend through the elongated body into the rifle bore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a short throat with a single tapered step and uniform depth rifling grooves is used, then the firearm structure is simple, but chamber pressure becomes high limiting powder capacity and muzzle velocity
Solution Approach 1:
The throat is divided into three distinct sections: a first tapered section, a cylindrical section with straight side walls, and a second tapered section. This segmentation allows each section to perform a specific function, reducing overall resistance to bullet movement and enabling lower chamber pressure compared to a single tapered step design.
Solution Approach 2:
Different sections of the throat have different geometric properties optimized for their specific functions. The first tapered section facilitates bullet engagement, the cylindrical section provides a transition zone with reduced drag, and the second tapered section prepares the bullet for rifling engagement. This local optimization of geometry reduces overall resistance and enables increased powder capacity.
2Ease of manufacture
If a short throat with a single tapered step and uniform depth rifling grooves is used, then manufacturing is simplified, but bullet misalignment occurs reducing accuracy
Solution Approach 1:
The throat is segmented into three sections with the cylindrical middle section having straight side walls that are parallel to the bore axis. This geometric feature naturally guides the bullet into coaxial alignment as it transitions from the first tapered section to the second tapered section, improving accuracy without significantly complicating manufacturing.
Solution Approach 2:
The cylindrical section with straight side walls performs a preliminary alignment function before the bullet enters the second tapered section and rifling engagement. This preliminary coaxial alignment ensures the bullet is properly positioned before critical rifling engagement occurs, improving accuracy while maintaining manufacturing feasibility.
3Device complexity
If uniform depth rifling grooves are used in a single tapered throat, then the rifling structure is simple, but resistance to bullet movement is high reducing muzzle velocity
Solution Approach 1:
The rifling grooves are distributed across three distinct throat sections rather than being formed in a single tapered zone. The gradual transition through the cylindrical section with straight side walls reduces the abruptness of rifling engagement, decreasing resistance to bullet movement and enabling higher muzzle velocities.
Solution Approach 2:
The geometric parameters of the throat are changed along its length, with the cylindrical section maintaining a constant diameter that provides optimal transition characteristics. This parameter variation reduces resistance to bullet movement compared to a uniformly tapered design, enabling increased muzzle velocity while maintaining manageable rifling complexity.
4Length of stationary object
If a single tapered throat step is used, then the throat structure is compact, but chamber pressure increases limiting powder capacity
Solution Approach 1:
The compact throat space is segmented into three functional sections that work together to reduce resistance to bullet movement. The cylindrical middle section with straight side walls provides a low-resistance transition zone that maintains compact overall length while significantly reducing peak chamber pressure, enabling increased powder capacity.
Solution Approach 2:
The throat geometry parameters are optimized along its length, with the cylindrical section providing a constant diameter zone that minimizes resistance. This parameter optimization allows the throat to maintain a compact length while reducing chamber pressure sufficiently to accommodate increased powder capacity for higher muzzle velocities.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design reduces resistance to the bullet's movement, allowing for increased powder capacity and muzzle velocity while ensuring coaxial alignment, thereby enhancing accuracy and performance.
Implementation Method 1
overall resistance to the longitudinal movement of the bullet is reduced
Data Source
AI summary
A firearm with a barrel that uses an ammunition discharge chamber that includes improved throat located between the chamber's free bore and the rifle bore. The improved throat includes a relatively short, inward aligned first step, an intermediate elongated cylindrical body, and a longer, inward aligned second tapered step. Formed on the inside surfaces of the first step, the elongated body and the second step are rifling grooves and lands that gradually their depths and heights from rear to front direction. The two steps are tapered inward between 1.0 to 1.5 degrees. Using a short first step, an elongated cylindrical body with straight sidewalls, a longer second step with continuous grooves and lands that begin gradually in depth and height from rear to front directions, chamber pressure is reduced thereby enabling more gun powder to be used and bullet misalignment in the rifle bore is reduced.