The bullet is made of nylon-coated aluminum and is nominally .358 inches in diameter. Test-firings to establish velocity and gather ballistic data show that the cartridges are within industry specifications for the plus-P rating. Velocities from a pressure test barrel averaged 2,300 fps. The bullets will not penetrate a Level II vest. The difference between lowest and highest velocity spreads indicates that the accuracy of Equaloy ammunition is more than sufficient for practical purposes. Variations depend on the particular handgun used, with the GP-100 and the Security-Six being very accurate, and the Smith and Wesson Model 10 revolver being less accurate. The accuracy tests were conducted at a range exceeding that at which most gunfights take place, but even the worst group recorded showed a spread tight enough for reliable center-of-mass hits at 25 years. In water recovery systems, bullets showed slight dimpling but no mushrooming or expansion. In a pine 2 by 4 inch block, there was complete penetration of the short side; in clay, the bullet left a cavity 3 inches deep and 3 inches in diameter. In an automobile, the bullet penetrated the outer skin and the inner trim panel. Despite the extremely high velocity, recoil is not so high as to cause flinching or degrade accuracy. Muzzle velocity in a 4-inch barrel is 2,112 fps and almost 390 foot/pounds kinetic energy; after traveling 200 yards, velocity is 575 fps and kinetic energy is 28 foot/pounds, with a 5-foot drop. 4 photographs.