Evaluation of Experimental Drive Springs for the XM19 Rifle
ARMY WEAPONS COMMAND ROCK ISLAND IL RESEARCH DEVELOPMENT AND ENGINEERING DIRECTORATE
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Laboratory tests and a theoretical study were conducted to determine the optimum design for increasing the life of the XM19 drive spring. Spring endurance tests were conducted by the Research Directorate of the Weapons Laboratory at Rock Island. Fatigue properties of eight experimental drive spring designs were evaluated under simulated firing conditions. The experimental springs consisted of various materials and strand constructions of 3, 7, or 14 wires. A theoretical study was performed by the University of Illinois under direction of the Research Directorate on the dynamic response of helical compression springs. The derived equations include the effects of spring mass and large deflections. Experiments were conducted and time-displacement records of impact-loaded springs were taken. Theoretical and experimental data were correlated and were in close agreement. It was determined from this investigation that of the eight experimental designs that were evaluated, the two-piece spring assembly was superior because it retained maximum loads at the completion of the endurance tests.
- Machinery and Tools