Shotgun Ammunition(組圖) | ||
文章來源: 豬鋼鬃 於 2009-12-24 21:43:04 | ||
Various shapes of shotgun slugs Shotgun cartridges are generally classified by gauge, which is a measure related to the diameter of the smooth shotgun bore and the size of the shell designed for that bore. Gauge is the number of equal sized lead spheres that weigh a pound and just fit into the barrel. Thus, the smaller the gauge number, the larger the shotgun bore. For example, one pound of lead divides into 12 equal spheres, 18.5 mm in diameter, and therefore 18.5 mm is the real diameter of 12 gauge shotgun bore. But .410 caliber drops out of this classification – it’s the measurement of the actual bore diameter in a fraction of inch (d=0.410x25.4mm = 10.4 mm). Nowadays 12 gauge is most commonly used in the world; 20 and 28 gauge with .410 calibre are also prevealing. Until mid-20th century 16 gauge was also widespread being very popular among European hunters, but today it’s mostly replaced with 12 gauge. Some exotic shotgun gauges like 10 and 4 are also awailable, but such cannons have limited application. Shotgun gauges
It is important to use appropriate shotgun cartridges that correspont to the chamber length of your gun. Modern shotguns usually have chamber length 70 mm (2 3/4”) and 76 mm (3”). Larger chamber length allows usage of more powerful ammunition. Thus, 12/76 ammunition is fit to be fired from 12 gauge shotgun with 76 mm (3”) chamber. Never try to use such ammunition with 12 gauge shotgun chambered in 70 mm – most probably it will cause barrel explosion. If the length of shell exceeds the chamber length (when placing 3” shell in 2 3/4” chamber), the shell will not be able to fully open and cause a constriction at the forcing cone. Hence, pressure inside the barrel tremendously increases that leads to damage of the gun and shooter. Basic ballistic characteristics of slug shotgun ammunition in comparison with some handgun ammo
12 gauge shotgun ammo12 Gauge is worldwide-accepted as standard in law enforcement and guarding services due to its high versatility and great firepower. Average slug ammunition 9provides sufficiently high accuracy at medium range (it is possible for ordinary shooter to hit 4” (in radius) circle from 75 m and 2” circle from 50 m). Fired from 20 m distance, 12 gauge slug penetrates steel house door. At this range it also penetrates rear end of non-armored automobile, a back seat, and still retains lethal energy. The most common type of ammunition for police use is a buckshot cartridge. Conventional police shell contains 9 pellets of 8.4 mm buckshot. One shot with this ammo is equivalent to 9 shots from 9 mm pistol. At 15 m distance such load covers 14.5” (in radius) circle target. At short range (15-20 m) this buckshot load penetrates door, rear end and a back seat of standard automobile, retaining lethal energy. The larger buckshot is, the greater its penetration ability. 20 gauge shotgun ammoIn spite of the fact that 20 gauge is distinctly smaller than 12, it retains great firepower. Due to this circumstance along with the fact that 20 gauge ammo produce considerably less recoil as compared to 12 gauge, this gauge gained wide popularity. In comparison with 12 gauge shotguns, 20 gauge ones are usually lighter and more maneuverable. .410 caliber shotgun ammoIt is prevalent point of view, that .410 caliber shotguns are not effective for self defense due to their insufficient stopping power. This opinion is not correct at all, because at short distances those are typical for self defense shooting, the kinetic energy of .410 caliber slug is comparable with the energy of extremely powerful .41 magnum revolver bullet, which outstanding stopping power is beyond question. According to the firepower level, we can place .410 slug shotgun ammunition in a one line with the most powerful handgun ammo. As we can see from the table displayed above, 12 and 20 gauge shotgun ammunition greatly surpass .410 ammo in energy, but it’s not the reason to regard .410 ammo as something deficient. But the matter of ammo selection for self defense becomes most important in the case of .410 caliber. Birdshot and buckshot shells are not effective enough to ensure considerable stopping effect, so slug .410 ammo is most suitable for self defense. Such cartridges as Winchester Super-X .410/3” contain 1/4 oz slugs and can be regarded as moderately powerful ammo; it’s not recommended to choose slug shells with less projectile weight. Unfortunately, it’s not easy to find heavy .410 slug ammo for defensive purposes, but DIY cartridges might be solution. We recommend to take 11-14 g slugs for making DIY shells and use metal cases.
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