Extended-Range Expanding Bullet With Fracture-Enabled Fluid Entry

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Solution Overview

Problem

Firearm projectiles with polymer tips often fail to expand at medium to lower impact velocities due to axial drag, leading to reduced accuracy and range, and conventional designs impede fluid entry into the projectile, necessitating higher impact velocity thresholds for expansion.

Innovation Solution

An expanding projectile design featuring a metal jacket with a tapered nose portion and an expansion configured tip made of high-density materials like steel, tungsten, or ceramic, which includes fracture regions to facilitate fluid pathways for consistent expansion at lower velocities, maintaining aerodynamic efficiency and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a hollow-point bullet design is used to improve expansion and kinetic energy transfer, then stopping power is improved, but aerodynamic characteristics deteriorate due to increased axial drag

Engineering Contradiction:

Improvestopping powerVSAvoidaerodynamic performance

Core Design Contradiction:

PowerVSSpeed

Solution Approach 1:

The bullet is divided into distinct functional segments: a hollow-point body for expansion and a separate polymer tip for aerodynamics. This segmentation allows each part to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The polymer tip is inserted into the frontal cavity of the hollow-point bullet, creating a nested structure where the aerodynamic tip resides within the expansion cavity. This nesting allows the bullet to maintain both hollow-point expansion capabilities and spitzer aerodynamic shape.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Speed

If a conventional polymer tip is added to improve aerodynamic shape, then aerodynamic characteristics are improved, but expansion capability deteriorates at medium to lower impact velocities due to axial drag and fluid pathway blockage

Engineering Contradiction:

Improveaerodynamic performanceVSAvoidexpansion reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The polymer tip incorporates localized fracture regions with specific material properties that differ from the main tip body. These regions are designed to fail at lower stresses, creating fluid pathways when needed, while the rest of the tip maintains its aerodynamic integrity during flight.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The polymer tip transitions from a static aerodynamic component to a dynamic structure that changes state upon impact. The fracture regions are designed to fail under specific impact conditions, transforming the tip from a solid aerodynamic shape into a configuration that allows fluid entry and promotes expansion at lower velocities.

Inventive Principle:

Principle #15Dynamics

3Strength

If high-density materials like steel, tungsten, or ceramic are used for the tip to improve durability and penetration, then penetration and terminal performance are improved, but manufacturing complexity increases

Engineering Contradiction:

Improvepenetration capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The bullet employs a composite construction combining the hollow-point body (typically lead or copper alloy) with a polymer tip that can incorporate high-density materials. This composite approach allows the high-density materials to be strategically placed only where needed for penetration, rather than requiring the entire bullet to be made of such materials, thereby reducing manufacturing complexity.

Inventive Principle:

Principle #40Composite materials

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 design ensures consistent projectile expansion across a wide range of velocities and distances, improving penetration and terminal performance, while maintaining aerodynamic advantages and resisting rough handling and tip deformation.

Implementation Method 1

the expansion configured tip includes fracture regions to facilitate fluid pathways for consistent expansion at lower velocities

Methodology Applied

Scientific EffectFluid pathways:

Implementation Method 2

conventional designs impede fluid entry into the projectile, necessitating higher impact velocity thresholds for expansion

Methodology Applied

Scientific EffectAerodynamic drag: Drag

Data Source

PatentUS12455150B2Extended range bullet

Publication Date: 2025.10.28 FEDERAL CARTRIDGE CO

AI summary

A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.