Surgical Experiences in South Africa, 1899-1900. George Henry Makins
of the many and varying factors which enter into its determination. The mere recital of some of these will suffice to make this evident.
1. Quality of the individual cartridge employed, as to loading, the materials employed, and their condition.
2. The condition of the rifle as to cleanliness, heating, and the state of the grooves of the barrel.
3. The angle of impact of the bullet with the part injured.
4. Resistance dependent on the weight of the whole body of the man struck, or of an isolated limb.
5. Special peculiarities of build in the individual struck, such as thickness and density of the integument and fasciæ, strength and thickness of the bones, &c.
6. State of tension of the muscles, fasciæ, and ligaments at the moment of impact, and fixity or otherwise of the part of the body struck.
7. The degree of wind, temperature, and hygroscopic conditions of the atmosphere.
These form some of the more important points which have to be taken into consideration, in addition to a mere calculation of the actual distance from which a wound has been received from a particular rifle, and taken with the unsatisfactory nature of the evidence as to the latter, which is usually alone obtainable, it is clear that definite assumptions are scarcely possible. In a great number of cases I came to the conclusion that the only indisputable evidence of low velocity was the lodgment of an undeformed bullet. There is little doubt, moreover, that the general tendency of wounded men was to minimise the range of fire at which they were struck, and again that in the majority of cases in this campaign it was quite impossible to determine whence any particular bullet had come, since the enemy was seldom arranged in one line, but rather in several. Again, smokeless powder was generally employed. Beyond this, in some cases where there was no doubt of the short distance from which the bullet was fired, the wounds were due to 'ricochet' of portions of broken-up bullets. The following instance well illustrates this. A sentry fired five times at two men within a distance of six paces, knocking both down. One man received a severe direct fracture of the ilium, the bullet entering between the anterior superior and inferior iliac spines and emerging at the upper part of the buttock. The entry and exit apertures were large but hardly 'explosive,' as a subcutaneous track four to five inches long separated them. Besides this both men had other lesser injuries; thus in the second two perforating wounds of the arm existed. The latter were not unlike type Lee-Metford wounds, and were regarded as such until a few days afterwards when a hard body was felt in the distal portion of one track and removed. This proved to be a part of the leaden core only, and the similar wound had no doubt been produced by a like fragment, the bullet having broken up on striking the stony ground.
Trajectory.—The comparative flatness of this depends on the construction of the rifle and the propulsive force employed, and varies as does velocity with the nature, excellence, and amount of the explosive, the correctness of the principles upon which the bullet is devised, and the mechanical perfection of its manufacture. Its importance naturally consists in the manner in which it affects the possibility of covering objects on a wide area of ground and thus creating a broad 'dangerous zone.' A bullet fired on level ground from any one of three of the rifles referred to later (Lee-Metford, Mauser, Krag-Jörgensen), sighted to 500 yards and fired from the shoulder in the standing position, will cover some part of an erect man of average height during the whole extent of its flight. A body of men within that distance is therefore in a position of extreme peril in the face of a good shooting enemy.
The importance of a flat trajectory is progressively lost, however, with any rifle, as the weapon is gradually sighted to greater distances. Thus when sighted to 2,000 yards the bullet from the Lee-Metford rifle rises 174 feet, and a whole army might comfortably be situated over a considerable area within that distance. The importance of flatness of trajectory is also influenced by the nature of the ground occupied by the combatants. Thus when the area to be covered consists in ground first rising then falling from the rifleman, the trajectory will become more or less parallel to the surface crossed, and the 'dangerous zone' will be correspondingly increased in extent. On the other hand, when the ground slopes away from the rifleman the rise of the projectile is exaggerated, and reaches its most limited capacity of covering an intervening space when the flight crosses a hollow.
Revolution of the bullet.—It only remains in this place to say a few words concerning the revolution imparted to the bullet by the rifling of the barrel. This ensures the flight of the projectile on a line parallel to its long axis, and notably increases its power of penetration.
Both these properties of the flight are to the advantage of the wounded, since, as already mentioned, the more exactly the impact corresponds to a right angle with the skin, the more limited will be the area of contusion, even if it be of the most severe character, while to the twist of the bullet must be ascribed a not inconsiderable part in the explanation of the ready and neat perforations of narrow structures which are frequently produced.
It has been pointed out that the Lee-Metford bullet turns on its own axis once in a distance of ten inches, while the Mauser revolves once in a distance of eight and eleven-sixteenths inches; hence not more than at most two revolutions are made in tracks crossing the trunk, and not more than half a full revolution in the perforation of a limb. None the less, no one can deny the influence of the one half turn of supination in entering a perforating tool of any description, both as preventing splintering, and in preserving the surrounding parts from damage.
Beyond this, the spiral turn of the bullet, by diverting a part of the transmitted vibrations into a second direction, must, in the case of wounds of the body, help to throw off contiguous structures, and while those that are in actual contact are more severely contused, the surrounding ones suffer somewhat less direct injury. It must be borne in mind, also, that rapidity of revolution does not fall pari passu with that of velocity of flight, but that the former undergoes a comparatively slighter diminution until the bullet is actually spent. Hence, the influence of revolution is felt, however low the velocity may be, provided sufficient striking force is retained to enter the body. A word must be added here as to the surface of a discharged bullet; this, in taking the rifling of the barrel, becomes permanently grooved. The depth of the groove differs with the variety of rifle. In the Lee-Metford the grooves are deep (.009), in the Mauser slightly less so (.007), but the surface of both bullets is comparatively roughened when revolving in the body, and this circumstance, since the projectile exactly fits its track, may influence the degree of the surface destruction of tissue, and somewhat aid in the clean perforation of bone, since a little bone dust is always found at the entrance aperture of a canal in cancellous bone.
During the campaign many varieties of rifle projecting bullets of widely differing calibre were employed by the Boers, many of whom as sportsmen preferred the rifle to which they were accustomed to a regulation weapon, and an illustration of a large variety of bullets from cartridges which I collected from arsenals and camps is given below (p. 96). The great majority of the men, however, were armed with small-calibre weapons of some sort, and as the wounds produced by these are of chief interest at the present day, I shall say little of any others, beyond an occasional reference to Martini-Henry rifle wounds which may be considered to represent approximately those made by large leaden sporting bullets.
From left to right: Martini-Henry, Guedes, Lee-Metford, (Spanish) Mauser, Krag-Jörgensen
The most important, as the most frequently employed, rifles projecting small-calibre bullets were the Krag-Jörgensen, Mauser, Lee-Metford, and Guedes, given in the order of increase of calibre (from 6.5 to 8 millimetres, or .254-.314 in.) in the bullets. As to the seriousness of wounds produced by these there is little to choose, differences in character being only those of degree. Such differences depended on the area of tissue implicated, corresponding with the calibre of the particular bullet, the comparative weight of the bullet, and the degree of velocity of flight maintained at the moment of impact. When, however, any of these bullets have been exposed in their flight to influences capable of causing deformity of their outline and symmetry,