Barrel Extension Feed Ramp Geometry for Ammunition Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current barrel extensions in firearms, such as the M4 and M16, suffer from inefficiencies due to steep feed ramp angles and rough surfaces, leading to cartridge jams, deformation, and reduced reliability, especially with modern ammunition types like the M855A1.
Innovation Solution
The design incorporates a barrel extension with reduced feed ramp angles, blended and radiused edges, and a contoured feed ramp divider to guide cartridges smoothly, reducing contact with the chamber and enhancing feeding efficiency and reliability across various calibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If steep feed ramp angles are used in barrel extensions, then the structure is simpler and easier to manufacture, but cartridge feeding reliability deteriorates due to jams and deformation
Solution Approach 1:
The patent modifies the feed ramp angle parameter from the conventional steep angle (typically 45 degrees or more) to a reduced angle (less than 45 degrees, preferably around 30-35 degrees). This parameter change allows cartridges to be fed more smoothly into the chamber, reducing deformation and jams, while still maintaining manufacturability through standard machining processes.
Solution Approach 2:
The patent applies blended and radiused edges at the feed ramp transitions and chamber entrance instead of sharp corners. These curved surfaces guide cartridges smoothly through the feeding path, preventing sudden directional changes that cause deformation. The radiused edges also reduce stress concentration points during manufacturing and operation.
2Ease of manufacture
If rough surfaces are used in barrel extensions, then manufacturing costs are reduced and production is simplified, but cartridge deformation increases and feeding reliability decreases
Solution Approach 1:
The patent specifies that only critical feeding surfaces require polishing or surface treatment, while other non-critical surfaces can maintain standard as-machined finishes. This localized approach to surface quality ensures reliable cartridge feeding where needed without unnecessarily increasing manufacturing complexity or cost across the entire barrel extension.
3Ease of manufacture
If conventional feed ramp geometry is used, then manufacturing is easier, but cartridge contact with chamber increases causing deformation and damage
Solution Approach 1:
The patent incorporates a contoured feed ramp divider that pre-aligns cartridges with the barrel bore axis before they enter the chamber. This preliminary alignment action occurs during the feeding process itself, ensuring cartridges approach the chamber in the correct orientation, thereby preventing contact-induced deformation and damage without requiring complex post-manufacturing adjustments.
Data Source
AI summary
A barrel extension usable with a firearm and a firearm having a barrel extension is disclosed. The barrel extension may include a barrel extension body extending along a barrel extension central axis between a barrel interface end. The barrel interface end may be configured to be connected to a barrel and the bolt receiving end may be configured to selectively receive a rotatable bolt of the firearm. The barrel extension may further include a plurality of barrel extension lugs at the bolt receiving end having bolt lug receiving openings therebetween, wherein each of the plurality of barrel extension lugs has a lug inner surface that is a first distance from the central axis, and each of the plurality of receiving openings have a receiving opening inner surface that is a second distance from the central axis. The barrel extension further includes a first feed ramp with a first feed ramp surface configured to guide a firearm cartridge, a second feed ramp with a second feed ramp surface configured to guide a firearm cartridge, and a ramp divider between the first feed ramp and the second feed ramp, wherein the ramp divider has a ramp divider inner surface that is a third distance from the central axis.