Another form of wobble is suggested by Nimier and Laval,[9] of which I can offer no experience. They suggest that, as rotation slows, the bullet may on impact wobble like a top before it ceases to spin. Probably the power of penetration possessed by a bullet wobbling in this manner would not be very great, but its effect would mainly be altered in the direction of an abnormal increase in the size of the aperture of entry, or possibly in the degree of comminution in fractures.
It is probable that some of the more serious wounds observed were merely the result of unusual forms of impact with normal flight on the part of the bullet. The majority, however, depended, in the case of the wound of exit, on deformation of the bullet within the body, or the propulsion of bone fragments with it, and, when both apertures were affected, to previous ricochet on the part of the projectile.
It is here necessary to give a short account of the more common deformities met with, and to refer to the special characters possessed by different types of bullet of small calibre which may affect the ease with which deformity is produced, and the degree to which it is commonly carried. The effect of ricochet is to lower the velocity of flight, and at the same time to effect certain alterations of form in the bullet. These with rectangular impact in the case of bullets travelling at a low degree of velocity consist in a bending and deformation of the tip; in the higher degrees, of bending, shortening, extensive destruction, or complete fragmentation. If the bullet makes lateral impact, only widening and flattening result, often with the escape of the lead core from the mantle. That a ricochet bullet may travel a considerable distance is shown by the following observations quoted from Nimier and Laval.[10]
From left to right: 1. Guedes; regular dome-shaped tip; mild steel mantle; thickness at tip 0.8 mm.; at sides of body 0.3 mm. 2. Lee-Metford; ogival tip; cupro-nickel mantle; thickness at tip 0.8 mm.; gradual decrease at sides to 0.4 mm. 3. Mauser; pointed dome tip, steel mantle plated with copper alloy; thickness at tip 0.8 mm.; gradual decrease at sides to 0.4 mm. 4. Krag-Jörgensen; ogival tip as in Lee-Metford; steel mantle plated with cupro-nickel; thickness at tip 0.6 mm.; gradual decrease at sides to 0.4 mm. The measurements of the sides are taken 2.5 cm. from the tip. Note the more gradual thinning in the Lee-Metford mantle.
Up to a distance of 1,700 to 1,800 metres the bullet may make several ricochet bounds. When the bullet strikes first at short distances (as 600 metres), it may make several bounds of from 300 to 400 metres: at moderate distances (as from 600 to 1,200 metres), bounds of 200 to 300 metres; and at distances above 1,200 metres, bounds of 100 to 200 metres. The length of the ricochet bounds depends on the angle of impact of the bullet with the ground, the nature of the slope of the latter, and the velocity of the bullet.
Putting aside the question of calibre and volume of the bullets we are concerned with, I believe the most important variations as serious effects of ricochet depend on the relative thickness and the composition of the mantles. Fig. 26 illustrates the relative thickness of the mantles in the Krag-Jörgensen, Mauser, Lee-Metford, and Guedes bullets. Given an equal degree of force and velocity on the part of the bullet at the moment of impact, the assumption is justifiable that the thinner mantles would tear or burst more readily in direct ratio to their relative thinness. I believe this assumption to be borne out by my own experience of the common deformities that occurred; but the great relative frequency with which Mauser bullets came under my observation, and the difficulty of forming any estimate of the velocity and force retained by any particular bullet at the moment of impact, make it impossible for me to express myself with the confidence which I should wish.
The second condition which influences the nature and degree of the deformities depends on the relative tenacity or brittleness peculiar to the metal employed in the manufacture of the mantles. In the case of the Lee-Metford this consists of an alloy of 80 parts of nickel with 20 of copper. The Krag-Jörgensen and Mauser are ensheathed in steel plated with cupro-nickel, and the Guedes has a plain steel envelope coated with wax.
Both as a result of experience in the field gained from ricochet bullets, and in the hospitals from bullets which had undergone deformation within the body, I am under the firm impression that the thin nickel-plated steel envelope of the Mauser bullet splits more readily than the thicker and more tenacious cupro-nickel envelope of the Lee-Metford, that the direction of the ruptures is more purely longitudinal, and the fissuring itself more extensive and complete.
I append below a series of deformities observed in Mauser bullets, some of which were collected on the field of battle, but all of which were familiar to me in bullets removed from the bodies of patients, except the complete disc shape shown in fig. 29. They correspond with specimens of which I made sketches at the time of removal from the body, but which I had not the heart to retain in view of the natural wish of the patients to keep them as mementoes of their wounds.
From left to right: 1. Slipper form; slight broadening and turning of tip. 2. More pronounced degree of form 1, with laceration of the mantle opposite the shoulder of the bullet. This is the weakest spot, for two reasons: the alteration in curve at this position, and the junction of the thickened point of the mantle with the thinner sides. 3. Lateral ricochet involving nearly whole length of bullet. Rupture of mantle from broadening of core opposite shoulder. 4. Similar lateral ricochet with extensive longitudinal rupture of mantle, the latter being turned out and forming a cutting 'flange.'
Slight indentations and deviations from strict symmetry of form of such degree as not seriously to influence the outline and nature of the apertures were very common. Beyond these one of the most frequent primary deformities was that we familiarly spoke of as the 'slipper form' (No. 1, fig. 28). This results from light glancing contact of the tip with a hard body: in it the mantle of the bullet is rarely fractured, and the deformity itself is of slight importance, except in so far as it may influence the direction of the wound track, which acquires a tendency to be curved. The tip of the bullet is slightly flattened and turned up, down, or to one side, according to the point struck. I saw this deformity frequently, both with Lee-Metford and Mauser bullets. Nos. 2, 3, and 4 are more pronounced degrees of the same type of deformity, accompanied by more or less extensive fissuring of the mantle. No. 4 illustrates the turning out of the longitudinally fissured mantle in such a way as to make a cutting flange. I have seen such bullets removed, and the variety is of some importance as materially increasing the cutting capabilities of the bullet, and augmenting its area of destructive action. No. 5, fig. 29, is the only form I have not seen removed, but such a bullet would account for some of the long irregular gutter wounds observed, if it retained sufficient velocity to strike with any force.
This form is of little practical importance, as the velocity retained by the bullet is low, and no perforating power would be retained. It is inserted separately in order to complete the series, shown in fig. 28.
Fig. 30 illustrates complete longitudinal fissuring of the mantle. Such mantles are common, and still more so are the opened-out sheets such as is shown still attached in fig. 29. Free mantles are often very numerous on stony ground, but are of little importance, since I never saw fragments of them removed or impacted. They probably travel a very short distance after their formation, and if they did strike would possess