Subsonic Projectile with Segmented Copper Insert for Controlled Expansion
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Solution Overview
Problem
Subsonic projectiles lack the necessary expansion and deformation to effectively engage targets due to insufficient propulsion force, making them unsuitable for automatic or semi-automatic firearms and ineffective in expanding upon impact, unlike supersonic projectiles.
Innovation Solution
Design of an expanding subsonic projectile with a body featuring a meplat and a hollow bore containing an insert with a tip, leading section, and waist, which expands when discharged from a firearm at subsonic speed into a wet target, utilizing a monolithic solid copper or brass construction to ensure predictable expansion and compatibility with magazine feeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If subsonic projectiles are constructed with a blunt profile to enable expansion, then expansion capability is improved, but the projectiles become unable to be fed via magazine into automatic or semi-automatic firearms
Solution Approach 1:
The projectile is segmented into multiple discrete petals (typically three) that are separated by slots, allowing the projectile to expand in a controlled manner while maintaining a compact feeding profile. Each petal can expand independently upon impact, providing the necessary expansion capability without compromising magazine feeding.
Solution Approach 2:
The projectile transitions from a rigid blunt profile to a dynamic structure where discrete petals can expand and deform upon impact. The petals are designed to remain compact during feeding but expand dynamically when encountering target resistance, achieving both feeding compatibility and expansion capability.
2Strength
If subsonic projectiles are constructed with a blunt profile, then expansion capability is improved, but the propulsion force becomes insufficient for effective target engagement
Solution Approach 1:
The projectile parameters are optimized by adjusting the petal geometry, slot dimensions, and material properties to achieve the desired expansion characteristics. The discrete petal structure with specific slot configurations allows controlled expansion that maximizes terminal ballistics while maintaining subsonic propulsion efficiency.
3Strength
If supersonic projectiles are used to ensure expansion upon impact, then expansion capability is improved, but the projectile cannot be effectively engaged by subsonic firearm systems
Solution Approach 1:
The supersonic expanding projectile design is adapted for subsonic operation by segmenting the projectile into discrete petals with slots. This segmentation allows the structure to expand upon impact even at subsonic velocities, as the expansion is driven by target resistance rather than supersonic shock waves.
Solution Approach 2:
The projectile parameters including petal geometry, slot dimensions, and material selection are optimized to achieve reliable expansion at subsonic velocities. The design transitions from relying on supersonic shock waves for expansion to using controlled structural flexibility and target resistance-driven expansion.
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
The projectile achieves predictable expansion and increased damage upon impact, allowing it to penetrate deeper and create multiple wound channels, while being compatible with automatic weapons, thus ensuring a cleaner kill and effective target engagement.
Implementation Method 1
the insert is adapted to direct a fluid flow within the bore towards the plurality of discrete petals when the projectile is discharged from a firearm at a subsonic speed into a wet target
Implementation Method 2
Both lead and copper-jacketed lead are sufficiently ductile to expand and deform when hitting virtually any barrier or target
Implementation Method 3
the insert and bore form a friction fit
Data Source
AI summary
An expanding subsonic projectile has a body that has a meplat and at least partially defines a hollow bore having a bore diameter. An insert is disposed at least partially in the bore. The insert includes an insert axis; a tip disposed on the insert axis; a leading section extending from the tip towards the meplat, wherein the leading section has an expanding section diameter along the insert axis from the tip towards the meplat; and a waist extending from the leading section towards the meplat. The waist has a contracting waist diameter along the insert axis from the leading section towards the meplat.