Bore Erosion and Accuracy of M16A1 Rifle
Final rept. Feb-Jun 75
ROCK ISLAND ARSENAL IL GENERAL THOMAS J RODMAN LAB
Pagination or Media Count:
An analysis was conducted on the performance of M16A1 rifles made by three manufacturers with the use of two kinds of ammunition and three rates of fire. Data include extreme spread and bore erosion gage measurements, each as a function of the number of rounds fired. Consistency is lacking in the experimental data, even though identical tests were performed. Probably, random vibrations of the gun barrel or other unknown phenomena may be the reason for inconsistency of spread data. Inconsistency in the penetration of erosion gages may be due to fouling deposits on the bore surface and to lack of properly designed tools for unique measurements. Large variations occur in the useful life of the barrels due to variations in manufacturing, ammunition, and firing rate. The typical rate of erosion is about one-thousandth of an inch per thousand rounds of fire. Gage Number 6 may be used to measure barrel erosion and ultimately to indicate when to discard the barrel. Erosion increases and useful life of the weapon decreases with increase in rate of fire. The useful life of the weapon may be approximated as inversely proportional to the two-third power of the firing rate.