Point Blank Range

[Bitmap]

Rant on:

I frequently read and hear about something being at "point blank range" or someone was shot at "point blank range" when the speaker or writer usually means "really close" instead of "point blank range."

Here is a reasonable definition of point blank range:

The point blank range of any gun is the distance out to which a hunter can hold right on this game and be assured of a hit within a vital zone of the animal. In other words, the hunter doesn't have to hold high or low to correct for the bullet trajectory.

This definition deals specifically with game animals but could easily apply to self defense, plinking, shooting steel plates, etc.

The short form is that point blank range is any distance you can aim right at your target and get a hit. Shooting at deer sized animals with modern high velocity rifles (.308, .270, etc.) this is well beyond 100 yards. This range is over 100 yards even with a .45-70 with black powder loads. For most self defense handguns the point blank range on a standing human is over 100 yards.

I prefer that words and terms be used correctly. Don't use the term "point blank range" when you mean "contact distance."

Rant off.

That is all.

 

[Zak Smith]

Excellent post. PBR for most 223/308/3006-class cartridges is 200-350 yards depending on primary zero distance.

-z

 

[littlegator]

For most self defense handguns the point blank range on a standing human is over 100 yards.

Apparently, I need to practice...

 

[Mot45acp]

Hows the Armalite working?

 

[fletcher]

What's the origin of the term "point blank"?

 

[highfive]

I need to practice too...

Good thread though I had a very false impression.

 

[Zak Smith]

Wikipedia:
http://en.wikipedia.org/wiki/Point-blank_range

 

[MinnMooney]

Webster's dictionary def. : "with a direct aim; directly; straight."

I'm not sure how or when this term started erroneously meaning "very, very close" to most people but that's exactly what most folks associate with PBR now-a-days.

 

[Jim Watson]

One definition I recall, in the days of muzzleloading artillery, point blank was the range that could be reached with the muzzle elevated no more than one bore diameter. 'Course by then you'd be loading grape if not cannister.

 

[Zak Smith]

It's all in the Wikipedia link...

 

[Dean C]

My rare response (taking exception to others).

I interpret the definition of PBR (other than Pabst Blue Ribbon) is that distance from the free source of a projectile (i.e., end of barrel) to where the projectile falls outside of a target zone. This is with the line of sight parallel with the barrel. In all cases the minimum would be 0. The maximum depends on ballistics.

I do not believe that PBR is intended to takes into account elevation adjustment using sight or scopes. It is line of sight parallel to barrel. Note that Wiki definition states “without adjusting the elevation of the firearm”.

With this interpretation, PBR will in fact be closer than with other interpretations.

If it were described as in previous posts, it has no real dimension. It can be anywhere depending on where you adjust the sights of the rifle.

dean

 

[.cheese.]

Thank you. I learned something today.

 

[ArfinGreebly]

Etymology

Taken from:

http://www.takeourword.com/Issue037.html

[Omitted: discussion of how the term does not apply to archery targets]

All the early (16th century) uses of point-blank come from artillery and do not refer to a target but to the angle of elevation of a cannon. In 1537, Niccolo Tartaglia, an Italian mathematician, published the first scientific treatise on gunnery and over the next ten years perfected the gunner's quadrant, an aid in aiming. This device consisted of two wooden arms at right angles between which was an arc marked with twelve divisions (known as points) with a plumb-line attached at the angle. To use the quadrant, a gunner inserted the longer of its two arms in the cannon's muzzle and read the point at which the plumb-line crossed the arc. When the gun was aimed vertically the plumb-line crossed the quadrant's arc at the twelfth division. This was called point twelve. When the gun was horizontal the plumb-line crossed the arc at zero. Back in the 16th century, most people still used Roman numerals and zero was still a foreign concept so instead of calling this reading point zero they called it point blank.

Another of Tartaglia's achievements was to demonstrate that a projectile always follows a parabolic trajectory. Despite this, gunners as late as the 19th century believed that a cannon ball, if fired horizontally, would travel horizontally at first and then it would suddenly drop. The distance to the point at which this drop was supposed to occur became known as point-blank range.

 

[Zak Smith]

Dean,

If the line of sight (LOS) is parallel with the bore, then the bullet starts off below the LOS (ie, the sight over bore distance) and drops from there. For example, it might start at -1.75" (typical for a bolt rifle) and will drop from there. Nobody sights in rifles this way-- it is impossible to get a "zero" at all with this method, since the bullet never rises vs. the LOS.

PBR is defined by a set of:

1. external ballistics (including bullet/BC, MV, environmental conditions), and

2. primary zero distance (ie, the angle between the LOS and the bore), and

3. the target size.

To achieve the furthest PBR for a given target diameter, the bullet needs to rise to no more than half that diameter at its maximum ordinate, and the PBR will be the distance where the bullet has fallen to again half the target diameter below the LOS.


The blue line is the LOS. The green line represents the same trajectory with a 100-yard zero. The red line represents the trajectory with a 200-yard zero.

For a target size of four inches, the 100-yard (green) trajectory has a PBR of about 180 yards. Note that the point of impact (POI) is below the LOS everywhere except the primary zero distance, and none of the margin above the target center (2") is used.

The PBR for the 200-yard zero (red) is 235 yards. Again note that this could be improved slightly by moving the primary zero distance out, because approx 1/2" of margin above target center is wasted (the maximum ordinate is about 1.5" at 125 yards).

 

[hksw]

I prefer that words and terms be used correctly. Don't use the term "point blank range" when you mean "contact distance."

Rant off.

That is all.

I was like that a few years ago but eventually let up and accepted that fact that most folks (entire population, not just gunnies) don't know/don't want to know/could care less about the actual meaning of the term. If the subject or term ever comes up in discussion (with anyone), I'll set the record straight. Otherwise, I don't even bother wasting energy thinking about how it's misused in the media, entertainment (movies), etc.

 

[Dean C]

I like the reference to "horizontal" that is in Arfin's post. That plays along with my thinking.

Also, Zak, I agree with your assessment of the distance between barrel center and scope/sight center as not enabling PBR to ever achieve "0". My reference to 0 was based on my thinking of LOS as the center of the bore in this case. LOS for my rifle would be through the sights or scope. Therefore, with the LOS as center of bore, there would be a 0 at the muzzle end.
I wasn't able to open your illustration so I cannot comment on your entire post but I believe I see your point of view.

What I find interesting is the absence of multiple published definitions that agree. I believe we're seeing a lot of "interpretations". That's what makes these discussions so great.

MY definition of PBR would be, "the shooting distance within which a target zone can be hit without aiming (something akin to point and shoot)".

dean

 

[Zak Smith]

You always have to aim-- I think your definition would be better served by ".. without compensating for bullet rise and drop."

 

[Dean C]

I did ponder over "aiming". That's why I added "akin to point and shoot".
I agree with your words.
dean

 

[mpmarty]

Sorry, I have labored for sixty years believing that "Point Blank" was a poor translation of the French meaning "the whites of their eyes" as blanc is French for white and the English "Point" was transmorgrified from some French word having to do with eyes. In other words, "don't shoot until you can see the whites of their eyes".