AFTE Store - Balloting Bullets: Exterior and Wound Ballistics of Balloted Bullets Physical Characteristics of Balloted Bullets and Associated Cartridge Cases

A number of mismatched cartridges can be readily loaded and fired in certain firearms without difficulty. Examples include .380 Automatic ammunition in 9mm Makarovs, 9mm Luger in 40 S&W pistols and .270 Winchester in 30-’06 rifles. The bullets ballot down the bore acquiring intermittent rifling marks and emerge with reduced muzzle velocities. Most of these bullets are not spin-stabilized and tumble in flight. As a consequence they have very poor exterior ballistic properties. In the case of 9mm bullets from a .40 S&W pistol, ballistic coefficients are on the order of 0.025 to 0.030 compared to values of .14 to .20 for spin-stabilized 9mm bullets weighing 115 grains to 147 grains. Bullet holes in clothing and entry wounds produced by these balloted bullets will frquently reflect their tumbling nature followed by relatively shallow bullet penetration depths in tissue due to yawed impacts and reduced impact velocity. The necks of the fired cartridge cases will expand to fit the chamber often without splitting. Nine-millimter Luger cartridges must be manually extracted and ejected from a .40 S&W pistol whereas .380 Automatic cartridges will cycle the action of a 9mm Makarov.