- Location
- WMU203, Alberta (YCT)
I disagree
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Point Blank Range - Obsolete...
- Thread starter angrygopher
- Start date
You need to know what your PBR is, since you may have to take a quick shot with no time for adjustments. If you do have time for adjustments, you would benefit from knowing what the correct adjustment or holdoff is for the current range, to get you a inch or 2 closer to POA. You really need to subtract your group size from your target size, since MPBR assumes 0" groups, most people are happy to assume 0" groups, but it isn't great.
- Location
- WMU203, Alberta (YCT)
And exterior ballistics is definitely not yours. Check out Archers’s Advantage, it even has on online demo of the ballistics for a 280 FPS arrow you can view for free. A McKenzie medium deer conveniently has a 5” 10 ring btw. With a sight dialed @ 40 yds, aimed at dead centre, If I misjudge the target and it’s actually 30 yds. I will still hit the top of the 10 ring. OTOH, I’ll hit the bottom of the 10 ring if the target is 43 and change.
I don't think you understand MPBR... that is; the distance at which you can aim with a dead on hold from zero yards to that distance without an impact outside of the kill zone, given that the KZ is often understood to have a 5" radius... but I prefer a 3" radius, to allow some margin for error.
Let's say your example is correct... there is 5" of drop from 30 to 43 yards when the POI is for 40 yards... where do you expect the impact to be at 5, 10, 15, 20, 25 yards? Certainly not in the KZ, hence, you do not have an MPBR of 43 yards as you seem to be suggesting.
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- Location
- WMU203, Alberta (YCT)
I’m using 40 yds because that’s what the AA demo had for a target distance and wouldn’t allow me to change it. As mentioned beforehand, somewhere between 28-32 yds is more practical. My hunting rig was around 290 FPS. Target 3D around 300-305, FITA 270 FPS.
BTW since you brought it up, which pin for 5 yds?
ETA- the 40 yd example does bring up an important concept, understanding the actual effect of misjudging. Also, there’s the issue of holding on entirely the wrong spot, which also reduces PBR effectiveness.
BTW since you brought it up, which pin for 5 yds?
ETA- the 40 yd example does bring up an important concept, understanding the actual effect of misjudging. Also, there’s the issue of holding on entirely the wrong spot, which also reduces PBR effectiveness.
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- Location
- WMU203, Alberta (YCT)
So you didn’t answer my question, which pin for 5 yds? Pretty important to know for hunting situations BTW.
yeh mate same, an then see how many times i need to take to kick a foot ball over to it ha ha! im 'pretty' good at judging distances now.... its either underr 300 or over 300 hahaha
Ok, friend, I did not answer your question because it does not apply to this discussion, quite the opposite, you asking the question clearly demonstrates that "a little" knowledge can be dangerous.
You ask which pin at 5 yards... first and foremost, you just refuted the use of MPBR in archery... with MPBR there is only one aiming point, hence one pin... anyone who has been in archery for any length of time would not argue that using a single/immovable aiming point without coupling it with Texas windage or some kind of "gapping" method, meaning you aim "dead-on" regardless of the distance to the target, will severely limit the distance at which you can shoot a deer sized animal and still keep your point of impact in the kill zone.
Next your question cannot be answered without more information, you ask "which pin at 5 yards?" Additional info would have to include the speed of the arrow, the distance the line of sight is above the flight path of the arrow, the distance at which each sight-pin (multiple pins = NOT MPBR) was zeroed for, usually ten yard increments, again demonstrating how archery is a poor application of MPBR. But if you would like to generalize here... it is basic knowledge that a projectile aimed for any distance down range must first begin below our line of sight, then rise up through our line of sight arcing above until the effects of gravity cause it to fall back down through the line of sight, at the point where the projectile crosses the second time, is the intended zeroed POI, after which the loss of velocity and effect of gravity due to the loss of velocity (distance over time) cause an accelerated effect on the projectile... clearly I cannot get into more detail than that here. Suffice it to say, that "in general" with rifles and a sight height of 1.5"-2", the projectile first crosses the line of sight between 25-40 yards from the muzzle. In archery due to the wider variations in anchoring points and sighting systems, and the greatly reduced velocity of the projectile (arrow), the arrow will first cross the line of sight between 5-8 yards from the riser of the bow, hence depending the speed of the arrow and then height of the line of sight above the flight path of the projectile, it is likely that the 30 or 40 yard sight pins will be close at 5 yards... again impossible to answer conclusively without more data.
Having asked that question though, I think that we clearly agree that archery is not a good use MPBR concept.
Gentlemen, in reference to the OP original question as to whether MPBR is obsolete. I believe that we have established that it is not and probabley will not be any time soon. In addition, there is no doubt whatsoever that the use of a range finder whenever possible is a definite advantage and a great asset for those longer shots. I like to use flat shooting guns, set up for MPBR around 250 / 300 yards, depending on the cartridge, and this in conjunction with a good range finder ( and a lot of practise) gives me the ability and confidence to go hunting whatever and feel that I am ready for whatever situation presents itself, like when that same coyote runs far enough that he feels that he is safe and actually sits down at 563 yards. This is when the range finder and .243 Win.(and that expensive scope with laser cut external target turrets) are worth their weight in gold. As some have said, use all the tools available and it will make you a more efficient killer. That`s what works for me. Happy hunting 
- Location
- WMU203, Alberta (YCT)
I have definitely made one glaring error (other than arguing on the internet ) When anyone is calculating MPBR for anything, the size of the projectiles group needs to accounted for. Further, MOA accuracy out of archery equipment AFAIK is still unheard of. IOW, I'm hoping for a PBR using a 5" kill zone (or more accurately cone) I have to take into account my average group size which needs to subtracted from the cone's size. So, as hoytcanon did rightly point out, it becomes very impractical for the casual bowhunter to use MPBR, even if one uses the far too generous 9" kill zone.
I concede hoytcanon - you're right, for the average archer. PBR isn't practical.
) When anyone is calculating MPBR for anything, the size of the projectiles group needs to accounted for. Further, MOA accuracy out of archery equipment AFAIK is still unheard of. IOW, I'm hoping for a PBR using a 5" kill zone (or more accurately cone) I have to take into account my average group size which needs to subtracted from the cone's size. So, as hoytcanon did rightly point out, it becomes very impractical for the casual bowhunter to use MPBR, even if one uses the far too generous 9" kill zone. I concede hoytcanon - you're right, for the average archer. PBR isn't practical.
New Camper
CGN frequent flyer
- Location
- Lurking in the woods near SFRC.
MPBR will become an obsolete concept when: game animals begin moving like sloths, never appear when you least expect it and the majority of shots are no more within MPBR...
This is not said to disparage the use of 100% accurate range establishment techniques/equipment (rather, reasonably accurate) for even the most humble of intellects knows gravity immediately works it's magic on bullets in flight.
Ballistics I took with me moose hunting: 30-06, 180gr spire, soft point MV ~2800fps
range drop(MOA)
0 -1.5 ... actual inch
100 0.0
200 1.8
300 4.4
400 7.5
Over 1' at 300 is a miss. For the record, I physically verified out to 300y and with a compensating reticle, range card disc in the flip up cap showed corresponding number for range.
44mag carbine: 240gr S&B SP at 1570fps
0 -1.5 actual inch
25 -1.7
50 -2.7
75 -1.6
100 0.0
125 2.0
150 4.2
175 6.7
200 9.3
At 150y, this projectile would miss a deer size target.
Not so much for the 44mag, but a 200y zero for the 30-06 would be a better set to take advantage of it's MPBR. When you have only a couple seconds to react, there will never be time for anything but mental calculation (and using holdovers, an animal can move a disastrous distance in the half second that bullet travels to 400y: such shots must be taken when it is accurately deduced the animal will be stationary for that time) at best, MPBR is a concept immortal as gravity itself.
This is not said to disparage the use of 100% accurate range establishment techniques/equipment (rather, reasonably accurate) for even the most humble of intellects knows gravity immediately works it's magic on bullets in flight.
Ballistics I took with me moose hunting: 30-06, 180gr spire, soft point MV ~2800fps
range drop(MOA)
0 -1.5 ... actual inch
100 0.0
200 1.8
300 4.4
400 7.5
Over 1' at 300 is a miss. For the record, I physically verified out to 300y and with a compensating reticle, range card disc in the flip up cap showed corresponding number for range.
44mag carbine: 240gr S&B SP at 1570fps
0 -1.5 actual inch
25 -1.7
50 -2.7
75 -1.6
100 0.0
125 2.0
150 4.2
175 6.7
200 9.3
At 150y, this projectile would miss a deer size target.
Not so much for the 44mag, but a 200y zero for the 30-06 would be a better set to take advantage of it's MPBR. When you have only a couple seconds to react, there will never be time for anything but mental calculation (and using holdovers, an animal can move a disastrous distance in the half second that bullet travels to 400y: such shots must be taken when it is accurately deduced the animal will be stationary for that time) at best, MPBR is a concept immortal as gravity itself.
I have definitely made one glaring error (other than arguing on the internet
I concede hoytcanon - you're right, for the average archer. PBR isn't practical.
Am I allowed to own a bow now?
Splitting hairs, but regarding the concept of PBR and the positioning of the projectile within the killzone (regardless of size), the killzone cannot be referred to as a "cone." The killzone is of determined size regardless of the range, whether it is five yards distant or five hundred yards distant. You are confusing moa accuracy (may be considered a cone for casual conversation purposes) with the concept of PBR killzone (size does not change regardless of distance).
A friend has a rangefinder and a couple years ago we were watching this second growth bowl for hours and hours calling moose and ranged numerous distances in case a moose came by in various locations.
No moose, but he had a grizzly bear and three cubs the size of adult bears come by to visit at 17 yards.
That's where the rangefinder was useful.
No moose, but he had a grizzly bear and three cubs the size of adult bears come by to visit at 17 yards.
That's where the rangefinder was useful.
- Location
- WMU203, Alberta (YCT)
No, you're inferring incorrect things that I'm intimately aware of. The killzone on any game animal can never magically increase, that's not gonna happen. If anything my own inabilities will shrink the size of the sweet spot over distance. Add to that aiming errors and the entire situation of shots over 30 yds archery or 300 yds rifle become a matter of ideal situations. That's even more so with archery, where that awesome advantage of beating the speed of sound is non-existent, even at 10 yards. (also MOA accuracy @ 30 yds would mean a Robinhood almost every shot, people like that claim to exist - I'm definitely not on that short list)
You misunderstood what I said... I was not suggesting that you or anyone can achieve MOA accuracy consistently with archery gear. What I am referring to is your use of the word "cone" when referring to "killzone" as it relates to the concept of MPBR... it is not a "cone," it is a specific chosen diameter (whatever you choose; 6", 8", 10" etc...), regardless of the target distance... you can choose whatever killzone diameter that you want to use for your personal MPBR settings, but that diameter does not change from 0 yards through infinity... it is not a fluctuating diameter "cone." And while I am clarifying, your suggestion that group size affects MPBR is not technically correct with regard to the actual MPBR. With MPBR it is "assumed" that every shot is aimed accurately and group size does not enter the equation... in reality that does not occur, which is why it is wise to consider group size AND consistency, and build in some margin for error by reducing the diameter of the utilized killzone... however, once the killzone diameter is decided upon, it is assumed that the POA is consistent... it is up to the shooter to set the appropriate limits based on their accuracy results.
My turn for a question; Do you use a single immovable sight pin or crosshair reticle or optic in your bowhunting?
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