A rifle may perform first rate at short ranges, and fail entirely at long, while a rifle which will fire well at extreme ranges can never fail of good shooting at short. In fact certain calibres, &c., &c., &c., perform best at certain distances, Points in a perfect rifle.and in the combinations of a perfect rifle there are certain points to be attended to, or the weapon will be deficient and inferior.
Velocity.
It is desirable to give a bullet as much velocity as it can safely be started with, and the limit is the recoil of the gun, and the liability of the bullets to be upset or destroyed, for as soon as this upsetting takes place, the performance becomes inferior, and the circle of error enlarged.
Degree of twist.
It is clear that a bullet projected with sufficient twist to keep it steady in boisterous and windy weather, must of necessity have more twist than is actually necessary in a still favourable time; hence a rifle for general purposes, should always have too much twist rather than too little.
Weight of bullet.
The weight of the bullet must be proportioned to the distance it is intended to be projected with the greatest accuracy; for it is a law, that with bodies of the same densities, small ones lose their momentum sooner than large ones. It would be madness to use a bullet ninety to the pound at nine hundred yards, merely because it performed first rate at two hundred yards; or a forty to the pound at two hundred yards, because it performed well at nine hundred yards. The reason is that a forty to the pound cannot be projected with as much velocity at two hundred yards, as the ninety to the pound can, because the ninety uses more powder in proportion to the weight of the bullet than the forty does. Again, the heavier bullet performs better than the lighter one at nine hundred yards, simply because the momentum of the light ball is nearly expended at so long a range as nine hundred yards, and its rotatory motion is not enough to keep it in the true line of its flight, whereas a heavy bullet, having from its weight more momentum, preserves for a longer distance the twist and velocity with which it started.
Calibre.
As weight of projectile is a leading element in obtaining accuracy at long ranges, and as the weight cannot be increased beyond a certain limit in small arm ammunition, hence a small bore is an indispensable requisite for a perfect rifle.
In the foregoing brief summary of the most important properties which should be possessed by a first class rifle, we have dealt in generalities, Result of Mr. Whitworth’s experiments.but we shall now record the experience of Mr. Whitworth, who has entered into the most minute details, and has pointed out the harmony which should subsist between the twist, bore, &c., and the projectile, in the combinations of a perfect rifle.