Point-blank range
From Wikipedia, the free encyclopedia
In external ballistics, point-blank range is the distance between a firearm and a target of a given size such that the bullet in flight is expected to strike the target without adjusting the elevation of the firearm (see also gun). The point-blank range will vary with the firearm and its particular ballistic characteristics, as well as the target chosen. A firearm with a flatter trajectory will permit a nearer minimum and further maximum point blank range for a given target size, while a larger target will allow for a longer point blank range for a given firearm.
In forensics and popular usage, point-blank range has come to mean extreme close range (i.e., target within about a meter (3 feet) of the muzzle at moment of discharge but not close enough to be an actual contact shot). Gunshot wounds from point-blank are identified by extensive powder burns as well as tissue damage from perforation by unburned grains of gunpowder.
Contents
1 History of term
2 Small arms and maximum point blank range
2.1 Maximum point blank range for hunting
2.2 Maximum point blank range for military use
3 Calculating point-blank range
4 References
History of term
The term originated from a precise, but slightly different, meaning in the 18th Century. The carriage of a cannon was normally constructed so that the muzzle was elevated slightly even when the carriage was on a horizontal surface and the elevation screw turned fully down. When it was fired, the ball would travel in a parabola, initially rising above the line of sight connecting the end of the barrel with the target. The point where it rose above the line — immediately in front of the muzzle — was called the first point blank primitive. The point where it fell below it, or sometimes where it struck the ground and bounced, was the second point blank primitive. Point blank range was the distance out to the second point blank primitive.
Point blank fire was fire at a target in which the gun did not need elevating. The target would lie either within point blank range, or slightly beyond it so that it would be hit by the first bound of the ball. It was felt that artillery was at its most effective against infantry or cavalry at this point as the unpredictably bouncing ball would be hard to avoid by a mass of troops. Different types of guns had different point blank ranges; for example point blank range was out to 342 yards (313 m) for a French 8 pound Gribeauval gun with a 2.25 pound (1.0 kg) gunpowder charge.
Fire at targets beyond point blank range was called direct fire, and would require the gun to be elevated.
In naval engagements, point-blank range was almost exclusively used from genesis of naval guns until the development of an effective self-propelled torpedo in the 1870s, even though the guns were actually capable of much greater ranges. Because a torpedo hit from a small vessel could sink even a large ship, the gun ranges anticipated for naval warfare opened out so that a ship would not be vulnerable to torpedo attack from its opponent. The range settled at around 6000 yards (5500 m) at the end of the 19th Century but during the First World War jumped to the limit of the range of the guns themselves, 15 miles (24 km) or more for larger calibres.
The need to measure and allow for the target's movement relative to the vessel carrying the gun led to much technical development in the period between about 1910 and the end of the Second World War. The most important one of these was the use of a separate organisation for aiming the guns, rather than the gunners themselves doing this using sights connected to the gun barrels. At the greater ranges the targets were no longer even visible to the gunners, crew in director towers or using radar now observing and correcting for the fall of shot. This in turn led on to further developments to perform the task in anti-aircraft fire where the ranges were nearly as great but the targets moved even more quickly.
Small arms and maximum point blank range
Small arms are often sighted-in so that the sight line and bullet path are within a certain acceptable margin out to the longest possible range, called the maximum point blank range. The range of distance inside the maximum point blank range is greatly dependent on the external ballistics of the cartridge in question; high velocity rounds have long point blank ranges, while slow rounds have much shorter point blank ranges. Other factors in the point blank range are the target size (which determines how far above and below the light of sight the trajectory may deviate), the height of the sights, and an acceptable drop before a shot is ineffective.
Maximum point blank range for hunting
A large target, like the vitals area of a deer, allows a deviation of a few inches (as much as 10 cm) while still ensuring a quickly disabling hit. A varmint such as a prairie dog requires a much smaller deviation, less than an inch (about 2 cm). The height of the sights has two impacts on point blank range. If the sights are lower than the allowable deviation, then point blank range starts at the muzzle, and any difference between the sight height and the allowable deviation is lost distance that could have been in point blank range. Higher sights, up to the maximum allowable deviation, push the maximum point blank range further from the gun. Sights that are higher than the maximum allowable deviation push the start of the point blank range out from the gun; this is quite common on varmint rifles, where close shots are never made, as it places the point blank range out to the expected range of the targets.
Maximum point blank range for military use
This sight setting for maximum point blank range is also referred to in the military as Battle Zero. Soldiers are instructed to fire at any target within this range by simply placing the sights on the center of mass of the enemy target. Any errors in range estimation are tactically irrelevant as a well-aimed shot will hit the torso of the enemy soldier. The current trend for elevated sights and higher velocity cartridges in assault rifles is in part due to a desire to extend the maximum point blank range, which makes the rifle easier to use.
Calculating point-blank range
A projectile falls due to gravity once it leaves a weapon barrel. All objects at the same geographic location fall with the same acceleration, denoted g, roughly 9.8 m/s2 (32 ft/s2). Velocity is a vector; the vertical component of any projectile's velocity can be treated separately from the horizontal component. If the barrel is horizontal and at height h above the ground, then Newton's Equations of Motion can be used to show that the range is approximately , where v is the muzzle velocity. This calculated range is reduced by air resistance, which depends on the shape of the projectile.
2007-05-30 08:04:28
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answer #1
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answered by outdoors.guy54 4
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It depends on the sights and the size of the accepted target at the time. If I accept an 8" kill zone, point blank range is the point at which the bullet drops more than 4" below my line-of-sight, assuming it never rose more than 4" above my line of sight. Because the latter is rare for most high power rifles, increasing the height of the sight for most rifles will also increase the point blank range. Maximum point blank range occurs when you sight the rifle so that the bullet rises completely to the top of your kill zone before falling back down. With a 250-yard zero, my deer rifle is sighted with a point blank range of approximately 325 yards. This is very handy in Nevada mountains.
2016-05-21 19:49:18
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answer #2
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answered by ? 3
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The term "point blank range" is no specific range. It simply means that you are very close to your target. Generally, it indicates that your target is so close that you can hit it without aiming. I have no idea where the term "point blank" actually came from but some people say that it means that the traget is close enough that you don't have to adjust your sights for elevation.
2007-05-30 12:58:31
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answer #3
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answered by Anonymous
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phvswbts has the right answer. The 'point blank range' today meens 'very close'. But the actual term is used to desribe the range that a bullet will strike on target. For example,(I'm making these number up so they are not accurate.) if I am hunting deer with a 30-30 and the 'kill zone' is 8 inches and I sight my gun in to shoot 4 inches high at 150 yards (that being the top of the 8 inch kill zone as measured from center) and at 275 yards the bullet drops 4 inches below point of aim. Then my point blank range for a 30-30 would be 275 yards. Comparing that to a 30-06 for the same target, at 200 yards it hits 4 inches high, and 4 inches below point of aim at 397 yards, then my point blank range for my 30-06 would be 397 yards.
2007-05-30 00:57:24
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answer #4
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answered by Charles B 4
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The Term Point Blank Range originally was a military term meaning close enough that you do not have to adjust a rifle's sights to hit a target. Many military rifles would have a "Battle Sight" setting or troop would be taught to set their sights at a particular range such as 300 yards, while it would be a little high at closer ranges and low at 400 yards it would still hit a man at anything in between. It was a general setting to leave the gun on. If troops had the opportunity to be more precise they could always adjust the range to something more specific.
2007-05-30 00:31:22
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answer #5
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answered by SW28fan 5
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All the others are wrong, and only a few of them pu tany thought into their answer. Point blank range, in common usage, is used to describe a close distance, where you don't have to aim.
What it ACTUALLY means is the distance from the barrel that the bullet travels without the bullet rising.
The bullet rises because of the rifling in the barrel causing it to spin. Kinda like when you throw a spiral in football.
2007-05-30 02:51:34
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answer #6
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answered by Anonymous
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The true meaning is lost but the term loosely refers to a distance where the shooter cannot possibly miss, but LESS than contact distance from the target. In other words, it does not define an actual distance. It could be a foot, or a yard from the target.
H
2007-05-29 23:18:31
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answer #7
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answered by H 7
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Point blank range is a term used by CSI's and coronor's office's. It means someone put a gun very close to a person and pulled the trigger. That can mean as close as touching the skin.
2007-05-30 11:34:39
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answer #8
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answered by dtwladyhawk 6
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Basically it's a distance where you can't miss. Usually considered between 8 feet and contact. Look at a person 8' away from you and point your finger at them. Do you think you would miss with a gun, I hope not. There is no real set measurement for "point blank" when you hear that just think ... close.
2007-05-29 18:09:20
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answer #9
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answered by Gonealot R 6
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I usually use the term when the distance of the target is so close that aiming is not necessary.
2007-05-30 03:19:42
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answer #10
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answered by amish_renegade 4
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Thanks to DJ for the link, and it's a shame all the others didn't know that. Some of us are hunters, and we spend considerable time working up loads, chronographing them, recording standard deviations, and adjusting our scopes for point blank range. I suspect there are even some of us old guys who can use old cartridges with our rifles set to PBR who can outshoot the youngsters with their "flat-shootining" magnums zeroed for some arbitrary distance.
2007-05-30 02:00:49
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answer #11
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answered by Anonymous
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