Skeeter has it pretty much. Think of your bullet flying thru a tube. If the inside of the tube is 6", the bullet will never touch the top of the tube and max point blank will be reached when the bullet falls below the tube. The advantage I find is that I set my rifle's up to shoot particular size game and use that game's vital area, or close to it, as my target size. ie: I only use my 243 for shooting coyote's. So I have it set to hold dead on for as far as the bullet will never leave a 5" vital area. That mean's from line of sight, the bullet will never rise more than 2 1/2" above line of sight. For me that is a zero @ 236 yds and a point blank range@ 270 yds. That is the sure thing and at some point beyond 270 yds, you need to srart raising the sight's. If it's 10" top to bottom on a coyote's chest, I would only have to hold half the depth of the chest at 350 yds. Much beyond that and it's time to start a different program.

In the end, MPBR gives you all your cartridge has to give befor you have to srart figuring drop. At 400 yds, the load drop's 17.2". If I had a target type scope on it with turret's, I'd just dial in 17 click up and be 1/4" low. At 18 click's I would be 3/4" high. But befor you need to resort to that, use what the cartridge has to give you.

I have a 6.5x06 that I'm thinking of comp. shooting to 700 yds. In the game I'm concidering, the targets at each station range from 175 yds to 700 yds. The smallest target is an 8" steel plate and the largest a 14" steel plate. So to not have to worry about adjusting anything for a good way's, I sight the thing in to shoot at an 8" target at MPBR. Hold on the center of the 8" steel plate and if the wind doesn't do me, I have a hit out to somewhere around 300 yds. Haven't got my read out here now or I could give you the right ranges.

Don,
I do understand and agree with all of that, but I think your vocabulary needs some reconsideration. The point blank range or point blank range yards is where the projectile falls below the line of sight equal to the maximum trajectory, which can be adjusted, as you stated. There are many factors when considering the point blank range yards, error, probably being the most important. So, the user or shooter must decide what the maximum trajectory will be based on the size of his target, his skill and the shooting conditions. Since his opinions on these factors will be brought into the equation, I think the term “maximum point blank range” would be a personal decision more than a fact, and no table would point to this. I don’t have any literature in front of me, but based on my knowledge of shooting the following are the only measureables that would apply;
- Near zero or near zero range yards (the first time the projectile passes through the line of sight and it’s associated distance)
- Maximum trajectory or maximum trajectory range yards (the distance the projectile travels above the line of sight, and at what distance down range this occurs)
- Zero or zero range yards (the second time the projectile passes through the line of sight, and also at a given distance)
- Point blank range or point blank range yards (the distance in which the projectile has fallen below the line of sight equal to the maximum trajectory)
- Supplemental range or range yards (the distance in which the projectile has fallen below the line of sight equal to twice the maximum trajectory)

So, maximum point blank range does not fit into this shooting logic, not at least on it’s own, and I have never heard of that term, which is why I asked. Since this distance (maximum point blank range) would take personal opinions into consideration, I don’t think it merits any association with a viable shooting term.

Respectfully,
KP

No Killer. Max point blank range is not when the bullet fall's below the line of sight but rather below a pre determined distence below the line of sight. That is why to change the MPBR you change the size of the target.

Think of it this way. Your shooting at two target's, one an 8" target and one a 6" target. Your rifle is sighted in at MPBR for the 8" targetand your shooting at the MPBR for the 8" target. A hold that when aiming at the center of the target will hit the bottom of the 8" target, go 2" under the 6" target. When ever you go beyond the MPBR of any size target, you then have to raise the sight's to get the bullet to hit the target. It's true you may not have to raise much but you will have to raise them to make a hit. If the above 8" target was at MPBR at say 200yds, you hold on the center of the target but it was moved to maybe 210 yds, you'll miss by shooting under the target. You needed to raise the sights somewhat to stay on the target. At the same time at mid range, the bullet will now go over the top of the same 8" target.

I just re-read my post and think I should say something about mid range also. When the bullet reach's the highest point in it's trajectory, it has reached mid range. When sighted in at an 8" target, at mid range the bullet will be 4" above the line of sight. If you raise the sight's 2" to compensate for a target beyond MPBR, the bullet will rise more than 4" at mid range missing high.

You are right that the bullet passes thru the line of sight two time's but remember that the line of sight is seen as the center of the target we're shooting at, not the bullet path. It's bullet path and target size that determine's MPBR.

MPBR is determined only by the ability of the cartridge, not the shooter. The shooter's abilities to hit vary depending on the shooter and that has nothing to do with MPBR.

I hate to beat this to death but here is the defination out of my Sierra manual:

"Point blank range is a concept that is very important to hunter's and silhouette target competitor's. The point blank range of any gun is the range distence out to which a shooter can hold right on his game or target. In other word's, the shooter does not have to hold high or low to correct for the bullet trajectory.........................As long as the range to a game animal is not farther than the point blank range of the gun, the hunter can aim at the center of the vital zone on the animal and be assured of a hit.............."

There is more on it in the manual, Eddition V 2nd Printing.

Don,
I think I understand what you’re saying, but respectfully, have to disagree. In your scenario you are shooting at a distance between the Point Blank Range and the Supplemental range. It is that simple. By aiming your rifle high on the target, you are making an educated guess, and that is all.

I’m sorry, but I’ve never heard of Maximum Point Blank Range, and you have not convinced me that it exists. Further to suggest that a “Maximum Point Blank Range” exists, would mean that there would also be a minimum, and now I’m really confused!

Point Blank range is a mathematical equation. If you have a gun and you decide that maximum trajectory is your first priority and you don’t want the projectile to go more than one inch above the line of sight, you have just predetermined all the other factors, assuming of course using the same projectile in all situations. Your near zero has just been decided, along with the maximum trajectory range yards, the zero range yards, the point blank range yards and the supplemental range yards, whether you understood or not, it all happened, it was all established by that one decision. But, if you decided that using the same gun and same projectile that you wanted to now shoot farther away and needed to move the zero range out further you could pick pretty much any distance you want, but you just moved your maximum trajectory up to higher than one inch, and predetermined all those other factors again, whether it was understood at the time or not.

There is no Maximum pointblank range and there is no minimum point blank range. Point blank range is only one measurement, and it is when the projectile falls below the line of sight to a distance that is equal to the distance of the maximum trajectory.

Respectfully,

KP

I don’t want to beat it to death either, but lets look at your definition, and I must say it is overly simplified. But, to say that it is simply to be able to aim at a target (in the center) and be able to hit it, without adjusting the point of aim (that part is important) and hit it at the furthest possible distance. You would, like you said earlier, hit the bottom of the target, and whatever distance the target is at when you strike the bottom, you are at the Point Blank Range Yards. Example given – if the maximum trajectory is 4 inches above the line of sight, you have reached the point blank range when the projectile falls down to 4 inches below the line of sight, no matter what the distance.

Now, here is where I believe that you (not me) got confused. You mentioned adjusting the sights in one of your earlier posts. This can be done one of two ways. First, you could simply aim high, (just changed the line of sight by the way) but now we’re not aiming in the center of the target anymore are we? We are making an educated guess as to how far up we need to aim to get that increase our distance, but we have done nothing to the settings of the rifle, so we have not changed the Point Blank Range Yards. Second you could adjust the sights to accommodate this longer shot, but what do you do to achieve this? You increase the maximum trajectory, which just gave you a maximum trajectory that is too high at closer shots. What does this mean? It means that you will now miss the shot if the target is closer, which blows the whole “Point Blank Range” meaning out of the water! Because you were aiming at the center (See bold text in previous paragraph) and you missed.

You can’t come up with some disclaimer that says “now you just have to increase the size of the target”. How do you do that? Run up and feed the deer a bunch of wholesome corn and hope that he grows real fast?

I think it is important to note this – The purpose of the point blank range it to provide the shooter with a distance that he knows he can shoot within and remain accurate. It is pretty much the industry standard that shooting past the supplemental range is where you start getting irresponsible.

Respectfully,

KP

Killer,

I think the part your having a hard time understanding is that MPBR has nothing to do with the ability of the shooter. It refers only to the cartridge when sighted in to hit a specific size target. When that happens it is the ability of the cartridge and the cartridge alone that is measured, not the user if he decide's to raise the sight's.

Concider for a moment the 14" target at 700 yds. With a 14" target, NO cartridge will keep a bullet within 7" of line of sight to 700 yds. Therefor the MPBR is quite a bit less and the trajectory mush be compensated for by raising the sight's. On my 6.5x06, the bullet I use falls99.2" inches below "zero" at 700 yds. Zero is less than MPBR but the only thing that matter's when you start raising the sight's is how far below the line of sight you are.

Here's the data on the load I'm using:

BC. .525
vel. 2900 fps
MPBR 286 yds
MPB zero 245 yds
deflection @ 100 yds +2.6"

Using this data if I expect to hit an 6" target at 350 yds I'll have to raise the sight or go under it. Then by raising the sight I'll shoot over that same target at mid range. It is because I have exceded the MPBR for that size of target and the velocity I'm shooting the bullet. Again, the MPBR is a measure of the ability of the "cartridge" when a bullet is fired at a "certain velocity" at a target of a "certain size".

My scanner is not working or I would be happy to e-mail you the defination from Sierra. Hope this help's.

Sorrry I hit the wrong key. My 6.5x06 is sighted in for a MPBR at a 6" target, not 8".

Don,
I am not having trouble understanding, but I think you are. If you were do decide that you were going to shoot at a 14” target at 700 yards and you’re gun (notice I didn’t say shooter) was not able to keep the projectile within 7” of the line of sight, you are simply out any type of “point blank range” that this weapon is capable of achieving. If the bullet were to fall two feet below the line of sight at 700 yards and have a maximum trajectory of two feet the target would have to be four feet to be with in the point blank range. If the target is smaller than four feet, you are shooting outside of the point blank range. Sure there are mathematical equations that would allow you to shoot at this target, and hit it repeatedly, mortar rounds have proven that, but don’t mistake this type of shooting for being with the point blank range of the weapon (not shooter).

Again, if one were to shoot at a target within its point blank range, you would hit it every time by aiming at the center of the target. The target would have to be somewhere in between the muzzle and the distance in which the projectile falls equal distance below the line of sight as the maximum trajectory. Point blank range is meant to allow for accurate shooting at a sensible target with in a given distance without adjusting the point of aim. And that is not what you are describing.

KP

I think you should go back and read Your definition. It is pretty clear to me, but doesn't support your arguement.