"Point Blank" vis-a-vis "Contact Wound"


PDA






Oyeboten
July 11, 2009, 09:58 PM
I notice many threads in which a poster is using the term 'Point Blank' when, they really mean 'contact wound'.


'Point Blank' is any situation there the fired projectile is able to strike the Target that is literally in the sights, without one's having to take into account any serious degree of parabola.


A 'Contact Wound' is an injury occasioned by the discharge of a Firearm when the Firearm is being pressed against the Body of a person or other Animal.


Point Blank...and Contact Wound...are not interchangeable terms.

If you enjoyed reading about ""Point Blank" vis-a-vis "Contact Wound"" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
General Geoff
July 11, 2009, 10:04 PM
Well technically, a contact shot IS a point blank shot. A point blank shot is not necessarily a contact shot.

Double Naught Spy
July 11, 2009, 10:16 PM
Unless you bore sight, a contact shot isn't point blank. A contact shot will be below where the sights indicate. A contact shot with a scoped AR-15 may be anywhere from 1-2" below where the scope is sighted.

highorder
July 11, 2009, 10:21 PM
Blame hollywood.

Lone_Gunman
July 11, 2009, 10:23 PM
Forensic pathologists confuse this issue, and will sometimes use statements like " the firearm was fired at point blank range " when they are really referring to contact, or near contact, wounds.

To a forensic pathologist, a gunshot wound sustained at point blank range would be associated with powder burns (in their minds).

freakshow10mm
July 11, 2009, 10:27 PM
Point blank refers to maximum point blank range which is the maximum distance a bullet will strike a given target size. Example: The maximum distance a bullet will strike a 10 inch diameter target, meaning it will not pass more than 5 inches above the center nor 5 inches below the center of the target, is the bullet's point blank range.

People that think point blank is up close don't have a clue what they are talking about. Educate them: http://en.wikipedia.org/wiki/Point-blank_range

Zoogster
July 11, 2009, 10:37 PM
The general use in society is as a very short range shot. Not only in movies but even the media, from the TV to newspapers, novels and most other forms of communication.

While the actual definition is as you describe which can be 50+ yards in some calibers, the majority of the population familiar with the term will instantly picture a shot from within a few feet of the target.
In fact since the vhast majority of the population uses the term "point-blank" to refer to such a shot, it has practicly been redefined.
Much like the term "clip" is universaly understood to refer to a magazine even though the term is technicaly incorrect for a box magazine.

The English language and words in it actualy do come to be redefined over the centuries, I think this specific term may be too far gone to save. If 95% of the population of the world come to use a term to mean a certain thing, the term has been defacto redefined to mean exactly that.

Jim K
July 11, 2009, 10:38 PM
Actually, point blank originally meant that the barrel of the gun was horizontal and the range was such that there was no need to take bullet drop into consideration. The term comes from a device called a gunners' quadrant, which was inserted into the muzzle of an artillery piece to determine elevation. The degrees were marked and the gunner knew that a certain elevation equated to a certain range given a standard charge and weight of projectile. The position at horizontal was unmarked, hence it was a "blank point" or "point blank."

Jim

Zoogster
July 11, 2009, 10:53 PM
Yes point blank is if you took a laser boresight and put it down the barrel, where the laser is pointing is point blank range. Anything else is not. So if the bullet is striking below (or above) that it is not point blank range. You can use the sights and have it sighted at something other than point blank range.
Some calibers can shoot point blank range from 50+ yards.

But the term is known to mean very close range in society. If you ever were to use the term point blank, and you meant the actual term not what society knows it as, you would have to explain. Even people that know what the term means would need to know if you were using the technical meaning or the common adjective in society.
So the term has been redefined because you cannot even use it or hear it used without the person hearing it being unsure of the implied meaning.
If you were to explain to someone you took an animal hunting from "point blank range" without citing the exact yardage they would picture near contact range (better example than self defense as most self defense is at near contact distances).
If someone told you the same thing, you would be unsure which usage they were using as well without additional details or explanation.
It has been defacto redefined by most of the population in most of the world.

ArfinGreebly
July 12, 2009, 12:37 AM
Extra points for anyone who can come up with the actual derivation of the term "Point Blank."

Any gunner's mate should be able to field that one.

Oyeboten
July 12, 2009, 01:06 AM
In Artillery...where sighting along the Barrel, the Target as-such is obscured by the Barrel?

scythefwd
July 12, 2009, 03:21 AM
zoogster,
The bullet starts dropping the instant it leaves the barrel (assuming a level barrel, it drops below the plane that the barrel is on in all cases). If what is directly in line with where the muzzle is pointing is the only place that is point blank.. then only a contact wound could be point blank. This assumes that we are correct about the object being in the same plane as the muzzle. The bullet center of mass will actually be below the center axis of the bore the instant it leaves the barrel. Using the strictest of weasel thinking, I could accept a margin of error of -.5(diameter of bullet) change in altitude before all of the bullet has left the plane that it's center was on originally when it was fired and still call it point blank..

I guess I always assumed (incorrectly) that point-blank meant .0 or .- range, which in other words would be 0 measured distance.

Elvishead
July 12, 2009, 03:51 AM
I actually learned something from this board.

JWF III
July 12, 2009, 08:04 AM
Yes point blank is if you took a laser boresight and put it down the barrel, where the laser is pointing is point blank range. Anything else is not. So if the bullet is striking below (or above) that it is not point blank range. You can use the sights and have it sighted at something other than point blank range.
Some calibers can shoot point blank range from 50+ yards.


Incorrect

Zoogster, read freakshow10mm's post. That is the true definition for Maximum Point Blank Range. And anything from 0 to MPBR would be point blank range.

Wyman

Jamie C.
July 12, 2009, 08:21 AM
Y'all sure find some interesting stuff to argue about.

And although I'm not going to get into what the technical term does or does not mean, I'm pretty sure that when the average person hears "point blank range", they probably think "can't miss" or "certain hit" range. And it would seem that's what both Hollywood and the news media intend as well.


J.C.

1911Tuner
July 12, 2009, 08:47 AM
Are we defining "Point Blank Range" or "Maximum Point Blank Zero?"

Maximum Point Blank Range is any range at which a rifle will hit a target of a given size without the need to adjust for bullet drop. Target size variable. For practical purposes, you don't want the bullet to rise or fall out of a 6-inch circle...or no more than 3 inches above, nor 3 inches below the point of aim. That is...the bullet strike at mid-range trajectory won't place it out of the circle, nor will it fall below the lower limit at the maximum distance.

Example given with a .308 rifle firing a 150 grain boat-tail spitzer bullet at a muzzle velocity of 2800 fps. A 250-yard zero will place the bullet somewhere within a 6-inch circle from touching distance out to about 325 yards. This is assuming a scope mounted 1.1 inch above bore centerline. Thus, 250 yards is the point blank zero for that rifle, firing that ammunition, using that scope.

Example 2. The standard ball ammunition for the .45 ACP has a theoretical maximum point blank range of 75 yards, assuming 2 inches high at 25 and zeroed at 50. This coincides with the Army's 75 yard maximum practical range for the service pistol.

Of course, other factors must be considered. The intrinsic accuracy of the rifle is the first. The center of the group may well be within the 6-inch circle...but individual shots may stray outside of if.

F'rinstance...

If the rifle will shoot minute of angle...theoretically at least...then the center of the 3-inch group will be on the upper line at 325 yards...but the divergence is 1.5 inches from the group's geographic center...so at least one shot will be 4.5 inches from the point of aim, which places it outside of the maximum point blank range.

Fascinating topic, ballistics.

The Lone Haranguer
July 12, 2009, 09:56 AM
A literal contact shot (muzzle directly in contact with skin) makes a more devastating wound than the projectile alone at a slight distance.

freakshow10mm
July 12, 2009, 11:24 AM
I think we are defining PBR. MPBZ is like you said, the exact distance from the muzzle where the POI and POA coincide.

I sight all my rifles in at MPBR. Easiest way to stay on target. Center sights on target center and squeeze. If target is within MPBR you will get a hit. Perfect for unknown distances. If your MPBR is 340y and you guess the target is 275y or so, just aim and let the magic of ballistics take it from there.

1911Tuner
July 12, 2009, 02:51 PM
MPBZ is like you said, the exact distance from the muzzle where the POI and POA coincide.

Nope. That's the zero...and there are 2 zeroes...or 2 points in the trajectory at which the POA and POI intersect.

The MPBR is the distance at which the bullet won't impact at more than a predetermined distance either above or below the point of aim at any point in its trajectory. Most riflemen like 3 inches above or below...or outside of a 6-inch circle.

Zoogster
July 12, 2009, 04:38 PM
Zoogster, read freakshow10mm's post. That is the true definition for Maximum Point Blank Range. And anything from 0 to MPBR would be point blank range.

Yes I oversimplified.
What a said would have simply gave a bore diameter maximum point blank range.
He gave a 10 inch diameter target point blank range, or 5 inches of drop from the center.

Neither is really suitable for civilian applications of firearms IMHO, and most references to the term for self defense and hunting with handguns (which generaly have much greater bullet drop than faster rifle calibers) are using a three inch drop reference.
It is not the military and simply hitting a torso is not acceptable. Most vitals are only a few inches in diameter and so a point blank range of a few inches is more realistic for hunting and self defense conversation.

Many people here claim amazing accuracy at the range, so you would assume thier point blank range diameter would be small enough to enable the benefits of thier abilities. If you are constantly drilling out the 1" bullseye of your targets, then a smaller point blank range is probably appropriate rather than a 5" drop as 10mmfreakshow gives or the standard 3" used by most catalogs in computing maximum point blank range on on a firearm and cartridge.



The reason thinking of it the way he describes is bad for others to learn as the definition is because you could make anything visible on the horizon "point blank range" by simply putting the firing platform at high elevation and determining the point blank range to a very large target at the same altitude (instead of 10 inches like his example, let's say hundreds of feet.) That would still technicaly be "point blank range" of hundreds of feet with hundreds of feet of bullet drop, distorted beyond any realistic usage of the term.

Since firearms are often expected to perform within 1-4 MOA and most regulation targets have a bullseye around 1" in height which many consistantly hit, point blank range means something different.
Simply hitting a torso size area is not acceptable, simply hitting a torso in hunting is inhumane, simply hitting a torso size area on a target with a 1" bullseye is unacceptable, so a 10 inch diameter is an unacceptable reference definition for most civilian applications.

Now if talking about artillery with a shell that has a blast radius of 50 yards, you have a very different point blank range requirement, and will as a result have a very different definition of "point blank range" when referenced casualy without reference to the exact diameter being described.

So I felt the boresight explanation was simple enough as it leaves firearms sighted beyond thier point blank range out of the equation and helps those unused to the term better picture what is being referenced. But clearly it was not a good reference.
The most important factor to clarify would clearly be what diameter the maximum point blank range being referenced is.


The largest factor in determining maximum point blank range is ususaly velocity due to the action of gravity. Projectiles in the air longer will be effected more by gravity. Of course drag, air density and other things factor in. Very fast rounds ususaly have a more distant point blank range.
Yet a round with a greater point blank range can end up having more bullet drop beyond the point blank range referenced, or within the useful range of the cartridge than a round with a better ballistic coefficient. So thinking of it as bullet drop is also not a good way to learn the definition. Further away a bigger but slower round can drop less than an initialy fast light round that normaly is defined with a more distant point blank range.
As a result it would even be possible to take two different cartridges and have one or the other with a greater "point blank range" simply be redefining the point blank range diameter of reference.
One may have a greater point blank range in a 6" diameter, and another in a 10" diameter where a greater ballistic coefficient has given it the edge.
So even just saying one round has a greater point blank range than the other is not always accurate without defining the maximum point blank range diameter being referenced.

kva47
July 12, 2009, 05:20 PM
Quote:
Yesterday 07:37 PM
ArfinGreebly: Extra points for anyone who can come up with the actual derivation of the term "Point Blank."

Any gunner's mate should be able to field that one.


Isn't it a french term? Aim for the center of the target, and the center of a target was traditionally white?

Vern Humphrey
July 12, 2009, 06:12 PM
"Point blank" is another one of those words or phrases which misused by people who have no undestanding of firearms. Other examples include:

"Clip" when referring to a magazine.
"Bullet" when referring to a cartridge.
"Going off half-cocked" when referring to someone doing something he is not prepared or qualified to do.
"Assault weapon" -- referring to any gun the speaker thinks looks mean.
"High powered" -- referring to any gun at all, other than a .22 rimfire.
"Cop killer" -- referring to any gun or ammunition the speaker thinks looks mean

freakshow10mm
July 12, 2009, 06:47 PM
Nope. That's the zero...and there are 2 zeroes...or 2 points in the trajectory at which the POA and POI intersect.
After I posted it, I thought about it. There are two points where they cross. That's right. Thanks for catching that.

freakshow10mm
July 12, 2009, 06:59 PM
The reason thinking of it the way he describes is bad for others to learn as the definition is because you could make anything visible on the horizon "point blank range" by simply putting the firing platform at high elevation and determining the point blank range to a very large target at the same altitude (instead of 10 inches like his example, let's say hundreds of feet.) That would still technicaly be "point blank range" of hundreds of feet with hundreds of feet of bullet drop, distorted beyond any realistic usage of the term.
Crunch the numbers for the possibility of that situation actually being used. If you feel it's a waste of time, then it's a bad argument.

Simply hitting a torso size area is not acceptable, simply hitting a torso in hunting is inhumane, simply hitting a torso size area on a target with a 1" bullseye is unacceptable, so a 10 inch diameter is an unacceptable reference definition for most civilian applications.
I don't hunt. I used the number 10 because it is a common number to use in an example. It just happens to be about the heart/lung height on a human torso which is what I aim for. If I misjudge the distance as under estimated, 400y instead of 350y, I'll most likely get a gut hit on my target which although not ideal, is acceptable considering the scenario in which I'd shoot at a human being.

Very fast rounds ususaly have a more distant point blank range.
Yes and some think this is a talisman. I hear a lot of praise of less drop for the various .30 magnums over the standard .30 cartridges, yet the MPBR difference is usually a mere 50-75y.

1911Tuner
July 12, 2009, 07:08 PM
Well, now...if we're talkin' about shootin' at people...that would fall under the heading of "Battlesight Zero" with is a different set of parameters. F'rinstance...the original '03 Springfields with the tangent rear sight would usually put a shot about 6-8 inches high at 100 yards with the rear sight at its lowest setting...the front sight in the "V" notch. That was sufficient precision for a man killer in a fast'n'furious firefight out to about 300 yards...where a hit anywhere on the torso above the knees was essentially a kill...regardless of whether the enemy soldier died in his tracks, or recovered and went on to see his grandchildren born.

Things changed a little when they went to the Garand and the M-14 due to the ability of the shooter to dial in the rifle for a 250 meter battlesight zero...and then use the marks on the graduated drum for longer ranges. All that was left for the rifleman to do was accurately estimate the range...dial in...hold and squeeze.

Jubjub
July 12, 2009, 07:22 PM
Stealing from Wikipedia:

The term point blank range is of French origin. The center of a target was once a small white spot and the French for white is blanc, and aim is point. So the term literally means, "aim at the center of the target." [2]

The term originated with the techniques used to aim muzzleloading cannon. The barrels of the cannon tapered down from breech to muzzle, so that when the top of the cannon was held horizontal, the bore actually sat at an elevated angle. In addition, the firing of the gun caused the muzzle to elevate slightly due to recoil, and this would result in an upward movement by the shot even in a cylindrical cannon. This caused the shot to rise above the natural line of sight very soon after leaving the muzzle, and later dropping below the line of sight due to the curved trajectory of the shot.

http://i88.photobucket.com/albums/k169/obviousfakename/6pdr_monument.jpg

A muzzle loading field gun. Notice the taper of the barrel.

http://i88.photobucket.com/albums/k169/obviousfakename/6pdr.gif

Just the tube. Notice that, due to the taper, when sighting along the top of the barrel, the bore will point slightly up.

If you enjoyed reading about ""Point Blank" vis-a-vis "Contact Wound"" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!