The difficulty in adhering strictly to the last table as far as the characteristic features of wounds are concerned is this: In battle the chances of ricochetting of bullets is said to be in the proportion of one to three. Naturally, the moment a bullet ricochets it loses more or less of its remaining velocity. The destructive lesion to be expected from a given shot at a given range against a certain resistant structure can not be depended upon to occur as it will when the shot is made with scientific accuracy in the shooting gallery against cadavers. _Trajectory_, or the curved line of flight of a projectile, has nothing to do with its wound-producing quality, except to increase the wound-producing frequency when it flattens and approaches the straight line of sight, because it will then pass through a greater portion of the space between the gun and the target, which may be occupied by men, without going over their heads. The greater the velocity, the flatter the trajectory becomes. The American, German, and Turkish rifles, with about the same trajectory, can be fired through a tube 24 inches in diameter at a range of 500 yards, and the vertical rise of the curve of flight would not hit the top of the tube. But where the range is increased to 1,000 yards it would be necessary to enlarge the tube to a tunnel, 15 feet in diameter, in order to fire the bullet through it without striking the top in its greatly increased curve in flight. _Velocity_ is the principal factor of the wound-producing power of the small-caliber bullet, although the latter quality is definitely related to the cross-sectional area and weight as well as to the hard metal jacket which preserves its form. The greater the velocity of any particular bullet the more serious is its wound. _Energy_, as the resultant of the components of _weight_ and _velocity_, represents the _real_ damaging quality, striking force, or “punch” of a projectile, with a variation in wound effect as the energy is distributed over the surface of the body, through the cross-sectional area and the form of the point of the projectile, and the elements of construction which a affect the preservation of its shape. As the energy is expressed in the formula, E = (WV^{2})/(2_g_), it is evident that the increase or decrease of the velocity factor gives greater variation than the increase of weight. _Range_ is important only as indicating the amount of _remaining energy_ which may be known to reside in the projectile at any stage of its flight. Without reference to the ballistic condition (velocity, weight, form, and construction, etc.) of a particular projectile, _range_ has no surgical significance. To the military surgeon, however, it is a term of the greatest interest when these ballistic conditions are known, as it gives him a very definite indication of the remaining energy or the damaging effect of a projectile at the different stages in its flight.