The current Army M6 electric blasting cap (DODIC M130) are used to initiate high explosives with suitable source of electric power. M6 blasting caps are used to detonate standard military explosives (C-4, TNT, etc.) and is used during combat and on firing ranges during training. The M6 electric blasting cap consists of a high explosive base charge – RDX, an intermediate charge – lead azide (LA) and an ignition charge – lead salt of dinitro-ortho cresol (DNOC) contained in aluminum alloy cup.
The M7 (DODIC M131) non-electric blasting cap is most similar to the Modernized Demolition Initiators (MDI) components of the Army inventory. Historical M7 malfunction investigations have suggested reliability issues with the current lead-based explosive mixtures. Currently M7 Caps are loaded with RDX as base charge, lead azide (LA) as an intermediate charge and lead styphnate (LS) as an ignition mix (or mixture of lead azide and lead styphnate) .
According to the Code of Federal Regulations 1910.1025 App A – Substance data sheet for occupational exposure to lead, Occupational Safety and Health Administration Standard Number 1910.1025 App A, “when absorbed into your body in certain doses lead is a toxic substance” and “Lead can be absorbed into your body by inhalation and ingestion,” which cause it to be both an occupational and an environmental issue. Personnel (Explosive Ordnance Disposal [EOD], Combat Engineers and Special Forces, and others) are exposed to lead. Therefore, elimination of lead is significantly important to the Department of Defense (DOD) and the emphasis of this project. The focus of this mission is to demonstrate that DBX-1 (Copper (I) Nitrotetrazolate), which is a “green” primary explosive, that has been developed to replace toxic/hazardous lead and mercury based compounds like LA and LS, is a suitable replacement for LA/LS materials in these blasting caps.
DBX-1 has been successful as a replacement for LA and LA/lead styphnate mixtures in multiple detonators and other small initiation components. It has comparable sensitivity to LA and is compatible with most common explosives and housing materials.
The Explosive Development Branch’s Primary Explosives and Detonator Lab Team and Stresau Laboratory INC. loaded and functioned DBX-1 M6 and M7 Blasting Caps substituting LA/LS as an ignition and/or intermediate charge and modified loading parameters set to replicate standard M6/M7 Blasting Caps already in the DoD’s arsenal.
Fabrication and testing was executed at U.S. Army Combat Capabilities Development Command Armaments Center (CCDC AC), Picatinny Arsenal, NJ Facilities, Stresau Laboratory INC., Spooner, WI.
DBX-1 M6 and M7 Blasting Caps Test data promotes confidence and suggests continued studies and testing to verify that replacing LA/LS with DBX-1 as an ignition and/or intermediate charge is suitable to effectively initiate the base charge with marked reliability. CCDC AC testing confirms the data by loading hundreds of caps in-house with DBX-1 however more work needs to be done at another manufacturing facility that has proper knowledge of handling and loading primary explosives. Currently, plan is to work with Battelle to load and test DBX-1 in both caps and do performance verification tests.
Blasting caps loaded with DBX-1 as a direct replacement for LA/LS intermediate/ignition charges have performed at a reliable and consistent measure. Additional testing and further exploration may lead to a complete undertaking of DBX-1 over legacy lead and mercury based primary explosive charges and mixes. Withdrawing the environmental/health hazard from legacy explosives and their components will enhance the Warfighters health risk posturing with regards to heavy metal toxicity exposure.