The Department of Defense, specifically the Navy, is seeking innovative solutions through the Small Business Innovation Research (SBIR) program to optimize the materials used in the 81mm M299 Ignition Cartridge (IC) system. The primary objective is to develop a new Tube Assembly that minimizes variability in bursting strength while aligning with historical performance requirements, potentially utilizing alternative materials instead of the current sulfate paper. This initiative is critical for ensuring the reliability and precision of the ignition cartridge during operational use. Interested parties should prepare to submit proposals by May 21, 2025, with the opportunity details available on the official SBIR website.

## Description

The current M299 IC system consists of the following critical components:a. Flash Tube Assemblyb. Tube Assemblyc. Firing Plugd. Heade. Black Powder Pelletf. Primer 150Dg. Body (drawing 9293428)h. Cap (drawing 9294756)&nbsp;The Tube Assembly contains the Tube as the base structure and the Heat Shrinkable Tubing that is applied to the exterior. The current Tube material is a sulfate paper produced using the Kraft wood pulping process and coated with paraffin wax. The current configuration of the Tube is spiral wound such that each layer of the Cartridge Paper is secured with adhesive. The Tube Assembly is positioned over the Flash Tube Assembly, secured to the IC body with adhesive, loaded with M9 flake propellant, and sealed with the Cap and applied adhesive.&nbsp;The current Tube dimensions are 4.770 +/- 0.015 inches in length, an inner diameter of 0.562 +0.005/-0.000 inches, and a thickness of 0.041 +0.000/-0.010 inches. These dimensions are required to ensure there is proper spacing within the ignition cartridge to provide a cavity for the propellant.&nbsp;The M299 IC specification (MIL-DTL-32247) allows for a wide range in Tube bursting strength. MIL-DTL-32247 paragraph 3.11 defines the bursting strength requirement as the following:a. “The tube shall not burst at a compression load of 57 pounds, minimum, but shall burst at a compression load of 192 pounds, maximum.However, the Army is currently analyzing historical test data to optimize pressure characteristics and tighten the bursting strength requirement. Variation in the Tube wall thickness directly affects bursting strength and therefore the pressure characteristics during the IC deflagration event. IC paper tube materials, design, and manufacturing control processes are critical to maintaining quality and reliability.”&nbsp;Currently, the Tube Assembly dimensional requirements allow for variation in the quantity of Cartridge Paper layers and subsequently affects the bursting strength, causing variability in pressure output. The thickness of the Sulfate Paper is a critical dimension as functional data appears to show a thicker paper and fewer layers causes increased variability in the bursting strength. Adhering to the historical TDP dimensional requirements is considered a significant factor in aligning with historical pressure characteristics and maintaining range precision requirements.&nbsp;The purpose of this SBIR topic is to prototype an engineering change to the M299 IC system to optimize the form, fit, and function of the Tube Assembly, minimize variability in the bursting strength, and align with historical range precision performance.&nbsp;The solution does not need to be made from paper. Alternative materials may be considered.&nbsp;Current Paper Requirements:<ol><li>Paper Properties:<ol><li>Standard Commercial Grade Paraffined Cartridge Paper</li><li>Color: Yellow No. 33538 of FED-STD-595</li><li>Basis Weight (gsm): 104 – 117 (Grams per Square Meter)</li><li>Grade: P03-05</li><li>Thickness (inch): .0047 to .0053; thickness of one spiral wrap of material</li><li>Tensile Strength: 75 lbs minimum along the grain; 20 lbs minimum across grain</li><li>Stretchability: 2.0% minimum along grain; 9.0% minimum across grain</li><li>Weight: 70 lbs per 500 24” x 36” sheets</li><li>Bursting Strength (psi): 70+</li></ol></li><li>Bursting Strength: MIL-DTL-32247 paragraph 4.58 defines the Bursting Strength Verification as the following:<ol><li>“The tube shall be cut in half lengthwise and one of the halves placed in the fixture. The stop shall be completely removed or backed off so that it does not touch the punch. Place fixture in universal tester set for a travel speed of 0.125 inches per minute. Proceed with Test Number 1 and 2.”<ol><li>TEST NUMBER 1: NO BURST: Apply 57-pound compression load, remove tube. Item is rejected if evidence of bursting is observed. Tearing or puncturing of material shall be considered evidence of bursting.</li><li>TEST NUMBER 2: BURSTING: If item is not rejected, replace it in fixture, using opposite end of tube and apply 192 pounds compression load. If item shows no evidence of bursting (punch travels through material), it shall be rejected.</li></ol></li></ol></li><li>Costs: The Flash Tube Assembly, of which the tube is a component, is estimated to cost $18. The redesigned tube should not increase the cost by more than 10%.</li></ol>

## Objective

Develop a suitable material that meets the M299 Ignition Cartridge (IC) Tube Assembly Technical Data Package (TDP) requirements and an engineering solution to optimize the current design while aligning with historical pressure characteristics and current range precision requirements.

## Phase I

Develop concepts for the paper tube technology that meet the requirements described above. Demonstrate the feasibility of the concepts in meeting Marine Corps requirements by material testing and analytical modeling, as appropriate. Establish that the concepts can be developed into a useful product for the Marine Corps. Provide a Phase II development plan with performance goals and key technical milestones, and that will address technical risk reduction.

## Phase II

Develop a prototype Tube to be assembled to the Tube Assembly for evaluation to determine its capability in meeting the performance goals defined in the Description. Demonstrate technology performance through prototype evaluation and modeling over the required range of parameters. Use evaluation results to refine the prototype into an initial design that will meet Marine Corps requirements; and for evaluation to determine its effectiveness in an operationally relevant environment approved by the Government. Provide thirty (30) complete Tube assemblies that will be used in a live fire mortar testing event. Prepare a TDP for submittal to the Joint Safety Review Board. Provide test support during the live fire testing. Prepare a Phase III development plan to transition the technology into Marine Corps use.

## Phase III: Dual Use Applications

Support the Marine Corps in transitioning the technology for Marine Corps use. Support the Marine Corps for test and validation to certify and qualify the system for Marine Corps use.

Materials Optimization for 81mm M299 Ignition Cartridge System

SBIR Opportunity Analysis

SBIR Documents

Related SBIR/STTR Opportunities

Opportunity Snapshot

Key Dates