armor army M4A1 military Sherman tank war weapon wwii M3A3 Stuart abstract angled angles appearance caterpillar-track continuous-track continuous-tread-band mobility movement propulsion tank-tread track-plates vehicle-propulsion weight-distribution wheels World-War-2-tank-track WWII-tank ammunition bullets cartridges death defense destruction destructive gun machine-gun mounted mounted-machine-gun pain weaponry World-War-2-tank wounding