Firearm Rifling Trailing Edge Geometry for Barrel Wear Reduction
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Solution Overview
Problem
Conventional firearm rifling fails to provide a complete seal between the bullet and the barrel, leading to reduced muzzle velocities and increased barrel wear due to friction, especially with copper-clad bullets, as the lands do not adequately engage the bullet surface.
Innovation Solution
The development of a rifle barrel with a rifling design featuring lands with a trailing edge face characterized by a land top to trailing edge ratio of no greater than 1:8, and a smaller land cross-section area, which allows for improved engagement and reduced deformation of projectiles, thereby enhancing the seal and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rifling with sharp-edged lands is used, then the lands can engage the bullet surface, but the friction increases and barrel wear occurs
Solution Approach 1:
The patent applies curvature to the land profile by creating a rounded trailing edge face instead of a sharp or flat edge. This curved configuration reduces the abrupt contact and friction between the land and the bullet surface, thereby reducing barrel wear while maintaining an effective seal. The rounded geometry allows for smoother interaction with the projectile.
Solution Approach 2:
The patent changes the geometric parameters of the land profile by controlling the land top to trailing edge ratio to be no greater than 1:8. This parameter modification optimizes the land configuration to achieve better engagement with the bullet while minimizing friction and deformation, directly addressing the contradiction between seal quality and friction.
2Reliability
If lands with larger cross-section area are used, then engagement with bullet is improved, but deformation of copper-clad bullets increases
Solution Approach 1:
The patent modifies the land cross-section area parameter by establishing a specific ratio constraint (land top to trailing edge ratio ≤ 1:8). This parameter control optimizes the land geometry to achieve adequate engagement with copper-clad bullets while minimizing the cross-sectional area that could cause deformation, thus resolving the contradiction between engagement quality and bullet integrity.
Solution Approach 2:
The patent applies different geometric characteristics to different parts of the land profile. The trailing edge face is specifically designed with a controlled ratio to optimize local engagement properties, while the overall land cross-section is minimized to reduce deformation. This localized optimization allows for effective engagement without excessive deformation.
3Speed
If faster twist rate is used, then spin rate on projectile is increased, but barrel length must be reduced
Solution Approach 1:
The patent changes the rifling geometric parameters by optimizing the land profile (top to trailing edge ratio ≤ 1:8) and cross-section area. These parameter modifications improve the efficiency of spin impartation, allowing for faster twist rates without requiring proportionally shorter barrels, as the optimized land geometry enhances engagement and energy transfer to the projectile.
Data Source
AI summary
An improve firearm rifling is provided in which the trailing edge face of the land is significantly longer than the rifling land top surface. The trailing edge angle between the trailing edge face and the level of the groove floor surface is a much smaller angle than conventional rifling land trailing edge angle, while the leading edge angle of the disclosed embodiments may be akin to a conventional rifling leading edge angle. Due to this, the present embodiments provide a rifling land profile that is nonsymmetrical, with the trailing edge face being at a much lower angle than the leading edge face which is configured in a more upright orientation.