In contrast to conventional spin-stabilized projectiles which derive their in-flight stability from the gyroscopic forces resulting from the high rate of spin, the finned projectiles are stabilized during flight by aerodynamic forces acting on the projectile. However, fin-stabilized projectiles are disadvantageous because the extra length of the projectile must be accommodated and the payload volume is comparatively low in relation to the projectile length. Fin-stabilized projectiles are advantageous because they follow the trajectory very well at high-launch angles, and they can be designed with very low drag thereby increasing range and/or terminal velocity. Such projectiles vary from 10:1 to 15:1 in length-to-diameter ratio. A sabot, wood or metal fitted around the projectile, is used to center the projectile in the bore and provide a gas seal. Additional stability is obtained by imparting some spin (approximately 20 revolutions/second) to the projectile by canting the leading edge of the fins.įin-stabilized projectiles are very often subcaliber. In high trajectory applications they tend to overstabilize (maintain the angle at which they were fired) and, therefore, do not follow the trajectory satisfactorily.įIN-STABILIZED PROJECTILES These projectiles obtain stability through the use of fins located at the aft end of the projectile. They perform very well at relatively low trajectories (less than 45° quadrant elevation).
#Types of guns with pictures full
Spin-stabilized projectiles are full bore (flush with the bore walls) and are limited approximately to a 5:1 length-to-diameter ratio. At a nominal muzzle velocity of 2800 feet per second, spin rates on the order of 250 revolutions per second are encountered. The rotating band is engaged by the lands and grooves. The projectile engages the rifling by means of a rotating band normally made of copper. Spinning is obtained by firing the projectiles through a rifled tube. Spinning a projectile promotes flight stability. Most guns in use today use spin-stabilized projectiles. The form of all projectiles is approximately the same, namely, that of a hollow steel cylindrical case with pointed head, having a soft metal band near the base which takes the rifling of the gun and gives the projectile the twisting motion which keeps it steady during flight. Some very significant progress in projectile design has been made in the past few years. Formal military classification is based on the intended use of the projectile and the composition of the explosive charge (i.e., antipersonnel, antitank, and incendiary). Projectiles can be broadly classified according to three main types: spin-stabilized, fin-stabilized, and rocket assisted (both fin- and spin-stabilized). While lead answered all the purposes in small-arms, it was found too soft for battering with larger guns, and stone shot being not only too light for good flight, but also deficient in tenacity, early gave way to iron. The projectile, as it is understood in modern times, came in with the use of gunpowder in warfare, and developed with the improvements in weapons using it. In the sieges of walled towns, in very early days, ballista, and catapults were used as a species of heavy ordnance, the former to hurl large stones, and the latter, wooden beams shod with iron and often covered with inflammable material. The first projectiles used were stones thrown from slings (afterwards lead bullets were projected in the same way), arrows from the long bow, and darts andjavelins thrown by hand. The principal function of the projectile is to carry its charge intact to the enemy's most vulnerable point, and its relative efficiency will be in a measure proportional to its carrying capacity. For guns of six-inch caliber and smaller they are called minor-caliber projectiles. Projectiles for guns of and above seven inches in caliber are called major-caliber projectiles. Large Caliber Ammunition - Types of ProjectilesĪ projectile or shell is a missle fired from the muzzle of a gun it is always the projectile, whether issuing from the muzzle of a Breech-Loading Rifle, using separate ammunition, or from the muzzle of a Rapid-Fire Gun, using fixed, cartridge-case ammunition.