Always Examine The Markings With A Magnifier:The markings that were applied to a metal surfaces of various military 1911/1911A1 pistols were applied both before and after the final polishing/finishing was done. Some specific markings, such as the final acceptance mark and the Ordnance Acceptance mark were always done after finishing. Other marks such as the standard slide manufacturers identification slide legend were always done before final finishing. Still other marks such as the serial number were (depending on the time period and the manufacturer) applied before, after and both before and after. An example of both before and after is the serial number of the post mid 1943 Remington Rands or Ithacas.
The “NO.” prefix was roll marked at the same time the right hand receiver legend (United States Pro…) was marked. Then after finishing and inspection, the serial number was stamped. 1911A1 pistols before mid 1943 had the serials stamped on before finishing. Early 1911 Colts up to about serial 7500 had their serials stamped after the finish was applied. This was about the same time that the serial number location was moved to below the trigger. Examining the markings will help determine if the pistol has been refinished, and it will certainly help to determine if the markings are original or counterfeit. However a thorough knowledge of what the markings are supposed to look like on any specific pistol is generally necessary. Markings that were applied before finishing will usually have all traces removed of the ridges created when the stamping die displaces metal. Often the ridges are hard to see. Another clue, especially on blued pistols, is around the stamps where metal is displaced, the finish will often flake off in microscopic chips that will leave a white shadow appearance around the letters. If the pistol is blued after these stamps, the micro flaking is highly unlikely. Only by studying lots of pistols will one know what he is looking at, and that is getting to be more and more difficult. Was the stamp before or after finish. These will be indicated in the descriptions below. These marks will have a white or burnished appearance. Also remember that when metal is stamped it is pushed a side and will create a ridge. A powerful magnifying glass is essential to see the ridges and the detail around them. If the ridge is absent and it should be there, The pistol most likely has been refinished. Refinished guns are worth much less then guns with the original finish.
The “NO.” prefix was roll marked at the same time the right hand receiver legend (United States Pro…) was marked. Then after finishing and inspection, the serial number was stamped. 1911A1 pistols before mid 1943 had the serials stamped on before finishing. Early 1911 Colts up to about serial 7500 had their serials stamped after the finish was applied. This was about the same time that the serial number location was moved to below the trigger. Examining the markings will help determine if the pistol has been refinished, and it will certainly help to determine if the markings are original or counterfeit. However a thorough knowledge of what the markings are supposed to look like on any specific pistol is generally necessary. Markings that were applied before finishing will usually have all traces removed of the ridges created when the stamping die displaces metal. Often the ridges are hard to see. Another clue, especially on blued pistols, is around the stamps where metal is displaced, the finish will often flake off in microscopic chips that will leave a white shadow appearance around the letters. If the pistol is blued after these stamps, the micro flaking is highly unlikely. Only by studying lots of pistols will one know what he is looking at, and that is getting to be more and more difficult. Was the stamp before or after finish. These will be indicated in the descriptions below. These marks will have a white or burnished appearance. Also remember that when metal is stamped it is pushed a side and will create a ridge. A powerful magnifying glass is essential to see the ridges and the detail around them. If the ridge is absent and it should be there, The pistol most likely has been refinished. Refinished guns are worth much less then guns with the original finish.
General dissatisfaction with the M14 and numerous studies led the Army to the development of a light weight weapon capable of firing a burst of small caliber bullets with a controlled dispersion pattern. Although opposed by the Ordnance Corp, the Armalite AR-15 was adopted by the Secretary of Defense as the 5.56mm M16 rifle. The M16 was selectable for full and automatic fire. The M16 was to have had the same effective range as the M14 rifle it replaced, but it was most effective at a range of 215 yards (200m) or less. The M16 used a 5.56mm (.223 cal.) cartridge in 20- or 30-round magazines. There were a number of problems encountered during initial fielding, but better training, preventive maintenance, and several design changes, resulted in the weapon that has become the standard issue rifle of the US Army , with some 3,690,000 having been manufactured.
The M16A2 semiautomatic rifle is the standard by which all military rifles of the future will be judged. This variant of the M16 fires a three-round burst in semiautomatic operation. The system incorporates an adjustable rear sight which corrects for both wind and elevation, a heavier barrel with 1-in-7 rifling, and a muzzle compensator to prevent muzzle climb during semiautomatic operation. The M16A2 is capable of firing all NATO standard 5.56mm ammunition and can fire 40mm grenades when equipped with the M203 Grenade Launcher.
The M4/M4A1 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. A shortened variant of the M16A2 rifle, the M4 provides the individual soldier operating in close quarters the capability to engage targets at extended range with accurate, lethal fire. The M4 Carbine achieves over 80% commonality with the M16A2 Rifle and will replace all M3 .45 caliber submachine guns and selected M9 pistols and M16 rifle series. The M16A2 5.56mm rifle is a lightweight, air-cooled, gas-operated, magazine-fed, shoulder- or hip-fired weapon designed for either automatic fire (3-round bursts) or semiautomatic fire (single shot) through the use of a selector lever. The weapon has a fully adjustable rear sight. The bottom of the trigger guard opens to provide access to the trigger while wearing winter mittens. The upper receiver/barrel assembly has a fully adjustable rear sight and a compensator which helps keep the muzzle down during firing. The steel bolt group and barrel extension are designed with locking lugs which lock the bolt group to the barrel extension allowing the rifle to have a lightweight aluminum receiver.
The M16A2 rifle is a product improvement of the M16A1 rifle. The improvements are:
a heavier, stiffer barrel than the barrel of the M16A1;
a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle;
a new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage;
an improved rear sight which can be easily adjusted for windage and range;
a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer;
a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure;
a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire;
a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.
The M16A2 semiautomatic rifle is the standard by which all military rifles of the future will be judged. This variant of the M16 fires a three-round burst in semiautomatic operation. The system incorporates an adjustable rear sight which corrects for both wind and elevation, a heavier barrel with 1-in-7 rifling, and a muzzle compensator to prevent muzzle climb during semiautomatic operation. The M16A2 is capable of firing all NATO standard 5.56mm ammunition and can fire 40mm grenades when equipped with the M203 Grenade Launcher.
The M4/M4A1 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. A shortened variant of the M16A2 rifle, the M4 provides the individual soldier operating in close quarters the capability to engage targets at extended range with accurate, lethal fire. The M4 Carbine achieves over 80% commonality with the M16A2 Rifle and will replace all M3 .45 caliber submachine guns and selected M9 pistols and M16 rifle series. The M16A2 5.56mm rifle is a lightweight, air-cooled, gas-operated, magazine-fed, shoulder- or hip-fired weapon designed for either automatic fire (3-round bursts) or semiautomatic fire (single shot) through the use of a selector lever. The weapon has a fully adjustable rear sight. The bottom of the trigger guard opens to provide access to the trigger while wearing winter mittens. The upper receiver/barrel assembly has a fully adjustable rear sight and a compensator which helps keep the muzzle down during firing. The steel bolt group and barrel extension are designed with locking lugs which lock the bolt group to the barrel extension allowing the rifle to have a lightweight aluminum receiver.
The M16A2 rifle is a product improvement of the M16A1 rifle. The improvements are:
a heavier, stiffer barrel than the barrel of the M16A1;
a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle;
a new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage;
an improved rear sight which can be easily adjusted for windage and range;
a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer;
a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure;
a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire;
a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.
The .22 Long Rifle rimfire cartridge is a long established variety of ammunition, and in terms of units sold is still by far the most common in the world today. The cartridge is often referred to simply as a .22 LR and various rifles, pistols, revolvers, and even some smoothbore shotguns have been manufactured in this caliber. It is occasionally referred to by its metric designation of 5.6x15mmR. The cartridge originated from the Flobert BB Cap of 1845, and was developed by the J. Stevens Arms & Tool Company in 1887[2] by combining the casing of the .22 Long with the 40 grain bullet of the .22 Extra Long. For many decades, it has been a very popular cartridge around the world. It is one of the few cartridges that are accepted by a large variety of rifles, as well as pistols. Virtually every manufacturer of cartridge firearms makes at least one model chambering it, and this has been true for more than a century. The .22 Long Rifle and related cartridges use a heeled bullet, which means that the bullet is the same diameter as the case, and has a narrower "heel" portion that fits in the case..22 LR is effective within 150 meters (490 ft), although practically this range will be much less. After 150 meters the ballistics of the round are such that the large "drop" will be difficult to compensate. The relatively short effective range, low report, and light recoil has made it a favorite for use as a target practice cartridge. The accuracy of the cartridge is good, but not exceptional; various cartridges are capable of the same or better accuracy. A contributing factor in rifles is the transition of even a high-velocity cartridge projectile from supersonic to subsonic within 100 yards (91 m). As the bullet slows, the shock wave caused by supersonic travel overtakes the bullet and can disrupt its flight path, causing minor but measurable inaccuracy.[citation needed]The trajectory of the standard high-velocity .22 LR with a 40-grain (2.6 g) bullet has a 2.7-inch (69 mm) rise at 50 yards, and 10.8 inches (270 mm) low at 150 yards, when zeroed for 100 yards (69 mm rise at 46 meters, and 274 mm at 137 meters, when zeroed for 91 meters).[5] A .22 LR rifle needs to be zeroed for 75 yards (69 m) to avoid over-shooting small animals like squirrels at intermediate distances.[5] The newest commercial rimfire, the .17 Mach 2, is based on the .22 LR case, but is slightly stretched in length (case length is similar to the CCI Stinger) and necked down. The light, aerodynamic .17 caliber (4.5 mm) bullet gives a much higher velocity than the .22 LR, for similar energy and a much flatter trajectory, but at the expense of increased cost and noise.
As a hunting cartridge, the .22 LR is mainly used to kill small animals such as rats and squirrels. It is also highly effective on rabbits at distances closer than 150 yards (140 m) and on ground hogs, marmots, and foxes closer than 80 yards (70 m). It has been successfully used on large creatures such as coyotes, but range should be limited to no farther than 65 yards (59 m); head and chest shots are mandatory with the most powerful .22 cartridge the hunter can use accurately. Hunters should find which cartridges, out of the various high-velocity and hyper-velocity ones, shoot well for them by preliminary testing.
A .22 LR bullet is far less powerful than larger cartridges, but dangerous nonetheless; in fact its deceptive "low-power" reputation can make it more dangerous for the fact that some shooters do not afford it the same respect as larger cartridges, and shoot it carelessly. It can easily kill or severely injure humans and large animals.[6][7] Users should therefore take great care to ensure there is no possibility of a stray bullet flying beyond its intended target and hitting someone or something else. Even after flying 400 yards (370 m), a stray .22 bullet is still traveling at approximately 500 feet (150 m) per second, which can inflict a very serious wound, and a standard .22 cartridge can have a ballistic range of up to a mile and a half (2400 m). Ricochets are more common in .22 LR projectiles than for those fired using higher powered cartridges as the combination of unjacketed lead and moderate velocities allows the projectile to deflect, not penetrate, and not be destroyed when hitting hard objects at a glancing angle.
ไม่มีความคิดเห็น:
แสดงความคิดเห็น