Chamber Insert Lock for AR-15 Barrel Extension Play

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Solution Overview

Problem

Modification of AR-15/M16 type firearms to accept a sub caliber action often results in a chamber insert adaptor exhibiting inter movement or play with the barrel extension, impeding the performance of the firearm assembly during loading and extracting of cartridges.

Innovation Solution

A sub caliber action device with a modified bolt assembly and a forward positioned chamber insert featuring radially projecting lugs that seat within grooves in the barrel extension, along with a spring loaded ball detent locking mechanism, to secure the sub caliber action to the upper receiver barrel, eliminating any looseness or play.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a chamber insert adaptor is installed in a modified AR-15/M16 firearm to accept sub caliber action, then the firearm can fire sub caliber ammunition, but the chamber insert adaptor exhibits inter movement or play with the barrel extension

Engineering Contradiction:

Improvecapability to fire sub caliber ammunitionVSAvoidmovement or play of chamber insert adaptor

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The chamber insert adaptor is segmented with multiple radially projecting lugs that can be independently positioned within corresponding grooves in the barrel extension. This segmentation allows the adaptor to maintain rotational stability while still accommodating sub caliber ammunition, resolving the contradiction between adaptability and stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The chamber insert adaptor is nested within the barrel extension, with the adaptor's radially projecting lugs fitting into grooves formed in the barrel extension. This nesting arrangement provides precise loc engagement that eliminates inter movement or play, allowing the firearm to fire sub caliber ammunition without compromising stability.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Stability of the object's composition

If the chamber insert adaptor is secured with a spring loaded ball detent locking mechanism, then the looseness or play is eliminated, but the device complexity increases

Engineering Contradiction:

Improveelimination of looseness or playVSAvoidlocking mechanism complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The spring loaded ball detent locking mechanism is designed to automatically engage and disengage the chamber insert adaptor with the barrel extension. The spring automatically pushes the ball detent into the locking position when the adaptor is installed, and the ball detent automatically releases when a charging handle is manipulated. This self-service mechanism eliminates the need for manual locking operations, achieving high stability without significantly increasing device complexity.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If the bolt assembly is modified to include a forward positioned chamber insert, then sub caliber action is achieved, but the loading and extracting performance is impeded due to movement or play

Engineering Contradiction:

Improvesub caliber action acceptanceVSAvoidloading and extracting performance

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The radially projecting lugs of the chamber insert adaptor are preliminarily positioned within the grooves of the barrel extension during assembly. This preliminary positioning ensures that the adaptor is precisely located before the bolt assembly is modified and installed, preventing any movement or play that would impede loading and extracting performance. The preliminary action of proper lug-groove alignment maintains high productivity while achieving sub caliber action.

Inventive Principle:

Principle #10Preliminary action

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 solution ensures optimal performance by maintaining the action receiver without any degree of looseness or play, enhancing the loading and extracting motion of the bolt during each cartridge cycle.

Implementation Method 1

spring loaded ball detent locking mechanism

Methodology Applied

Scientific EffectSpring: Spring

Data Source

PatentUS8726560B2Chamber insert lock installed within an AR-15/16 barrel extension for locating and reducing movement of an associated sub caliber action

Publication Date: 2014.05.20 22 EVOLUTION

AI summary

The present invention teaches an insert locking mechanism incorporated into a sub caliber action device, installable within an upper receiver of an AR-15 type firearm, and which interfaces with an upper receiver mounted forward assist for use with such as .22 caliber ammunition and in order to eliminate movement or play of the chamber insert adaptor associated with the substituted sub caliber action. The mechanism includes a generally cylindrical shaped body supported upon the action and exhibiting a plurality of radially projecting and circumferentially extending lugs which are configured to mate and seat within a plurality of grooves circumferentially arrayed within a barrel defined in the upper receiver.