Comparison Between Simulated and Experimental Results for a Balanced- Breech M256 Cannon System

摘要

Numerical simulations indicate that a mass-balanced system, with realistic tolerances and boundary conditions, would drastically reduce the motion of the gun tube during the projectile in-bore cycle. It was further postulated that such a system could significantly reduce projectile dispersion, as well as diminish the computer correction factors for different ammunition types. Several simple devices were designed and manufactured to achieve this desired effect on the actual recoil system. Then, a series of tests was conducted to duplicate what had been observed in the gun dynamics computations. The first set of experimental test firings employed an M256 in a hard-stand mount while following experiments incorporated in the system in an M1A1 Abrams tank. Specifically, a set of steel blocks was attached to the breech, which caused the centroid of the breech to coincide with the barrel centerline in both the vertical and horizontal directions. Additional modifications were made to both the fixed and adjustable kick blocks that guide the breech. The limited results showed that the muzzle-pointing angle at shot exit was reduced when compared to the baseline standard gun. However, later shots from an MlAl were inconclusive. This report details the modifications and reviews the observations. In addition, some possible explanations as to the outcome are offered.