Where is your zero?

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EmptyTin_Tim said:
Hope your dog gets better!

So by Point Blank Range... does that mean if I just hold true like cross hair intersection right on the target that is the range it will be within 1/2 " of the target??
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If your PBR was set with a 1/2" window, then every distance your D.O.P.E. states is a ZERO distance ... Then it will be + or - 1/4" anyplace within this range.
As well ANY determined hold position will also share this +/- 1/4" tolerance.

No good for accurate shooting .. more like close in most instances :eek:
 
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Motorhead said:
Something to Understand .. While applying as well Reading responses

In ballistic programs you have manual control over HOW LARGE or SMALL the calculated "Zero" window is. As such you are saying that if using a 1/2" acceptable window for POA then errors of 1/4" up or down from a true zero point is used in the calculation of the D.O.P.E. data :cautious:

So as stated, say your actual trajectory has the pellet / slug passing by intended target on the low side of this 1/2" calculated window, and your ranging is a few yards or more further out .... YUP you may very well hit low or miss entirely. Flip it and say your at the upper end of the 1/2" window & targets closer ... Yup hit high or go right over the top of intended target.

This is WHY in competitive air gun shooting at varied distances every other shot, precision calculated POI is so key !!!!!
Myself and likely others have there POI window at .100" ... or less than a 1/8"

So as we determine a distance to intended target, we always keep track of where ABSOLUTE POI is in theory intended upon target at any determined distance. This makes sneaking in shots that may be in the realm of a ranging error +/- or wind etc that much more under the shooters control.

PRECISION information = your best chance to hit where you actually are aiming.

As we often say in the FT game ... We Live and Die by the accuracy of our D.O.P.E. and being *Level (* another thing many don't fully grasp )
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Motorhead said:
If your PBR was set with a 1/2" window, then every distance your D.O.P.E. states is a ZERO distance ... Then it will be + or - 1/4" anyplace within this range.
As well ANY determined hold position will also share this +/- 1/4" tolerance.

No good for accurate shooting .. more like close in most instances :eek:
Click to expand...

Well look at this! It changed the far zero from 39 to 33 when I used your helpful suggestion of a smaller kill zone. (0.1")
Screenshot_20230517_141152_ChairGun.jpg


So my current set up of 30 yards isn't as far off of optimum as I thought! Plus as you explained, I definitely prefer .1 inch over a half inch margin.
 
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EmptyTin_Tim said:
Hope your dog gets better!

So by Point Blank Range... does that mean if I just hold true like cross hair intersection right on the target that is the range it will be within 1/2 " of the target??
Click to expand...

Thanks. Just fed him some rice and lamb. Hopefully he holds it down.

Point Blank Range, often referred to as PBR or MPBR is simply the range from which ones Point of Impact (POI) will be half of their kill zone low or high.

Using the examples I wrote in Post #30, if your PBR was 39.6 yards and you used a 1/2" kill zone, then we would expect the following.

POI would be 1/4" low at 17.0 yards.

POI would be 1/4" high at 30 yards.

POI would be 1/4" low again at 43.4 yards.

There would also be two zeros where POI would not be high nor low. One of those is 39.6 yards. The other I didn't note when I ran your numbers, but it would be somewhere between 17 yards and 30 yards.

Now let's go to the apex of trajectory of 30 yards and a 1/2" kill zone.

POI would be 1/4" low at 19.4 yards.

POI would be 1/4" low again at 38.3 yards.

In this case there would only be one zero.

If you increase your kill zone, the PBR will increase. If you decrease the kill zone, PBR will decrease.

I like PBR so I can take quick shots within that range without holdover. With a 1/2" kill zone and the specifications of your rifle, I have an extra 7.5 yards of range I can hit a 1/2" target without holdover.

For the record, I mean no holdover given shooting pests. 1/4" high or low typically doesn't matter for me.

If I was trying to hit the last spinner on a test your limits type target, then I would use holdover. Or just move to my zero distance.
 
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Scouty said:
If you increase your kill zone, the PBR will increase. If you decrease the kill zone, PBR will decrease.

I like PBR so I can take quick shots within that range without holdover. With a 1/2" kill zone and the specifications of your rifle, I have an extra 7.5 yards of range I can hit a 1/2" target without holdover.
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No ... it actually simply moves your probability of a hit closer to a critical point of missing !!
I'm not a physical bench rest & will assume no one is out in the field :LOL:

An airgun pellet for practical conversation is at NO TIME shooting perfectly flat ...
The TIGHTER one holds to a true PBR the more tolerance there becomes to wiggles and wobbles while taking said shot ... Fact !!!
While we're mostly speaking of vertical, the way one holds and shoots generally creates in application more a ROUND placement the shot may go ?

Folks will get LAX on the Up/Down and much as the Left/Right if there thinking is they have lots of room ( As in a larger POI window )

Now I teach precision shooting at the club level, Have been an Air Gun event match director for over 10 years. I'm not trying to stand on a soapbox & shout gospel on the subject ... Knowledge is power !! If you learn it and Do Not use it then that is a choice made. To state something that is counter to wanting or wishing to learn it is Ignorance. It too can be fixed by some simple education on how to shoot precisely.

Just sharing ... ;)
 
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I have the 2289 zeroed at 25 yards with 6 pumps and when I go to 15 yards 4 pumps make it zero. The few times I shoot in the garage 7 yard 3 pumps and its just about zeroed. I've even tried it once at 50 yards with 10 pumps and if I remember I had to holdover 1.5 dot??? To be honest I just wasn't a fan of pumping it 10 times for long so I did not shoot it but once at the 50. This is why I like the multpumps 🎯
 
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Simplemann said:
I have the 2289 zeroed at 25 yards with 6 pumps and when I go to 15 yards 4 pumps make it zero. The few times I shoot in the garage 7 yard 3 pumps and its just about zeroed. I've even tried it once at 50 yards with 10 pumps and if I remember I had to holdover 1.5 dot??? To be honest I just wasn't a fan of pumping it 10 times for long so I did not shoot it but once at the 50. This is why I like the multpumps 🎯
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I use the pump method with my Sheridan. Four pumps at 25y. My range is 80 feet= five pumps. 7 pumps at 45-yards where I have a target. 8 pumps max for the gun at 50 yards.
 
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Motorhead said:
If using HOLDOVER for POI differences over differing distances .... *ONE ZERO & that being based upon pellets weight, speed and scope height.
When NOT zeroed at pellets flight apex (* For most this falls in the @ 23 to 35 yard distances ) you will have 2 zeros and a span in distance where a HOLD UNDER to get a correct POI would be required .. Thats bad and will create unnecessary miss's
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Apex zero is the way to go! That is how all of my optical scopes were zero'd.
 
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My zero really depends on the power level of the airgun. I do the basics (Scope height, twist rate, velocity) on Strelok Pro to find my optimal zero. With most of my airguns shooting in that sweet spot of 880 fps, my zero is usually anywhere between 25 to 30 yards with no hold under. Once it's confirmed, I move it out to 100 yards and fine tune it. If Strelok says to dial 3.2 mils up but the actual holdover is 3.4 mils, I change the elevation in the Trajectory Validation and use the velocity it calculates. All this goes out the window on different days depending on wind direction and the amount of wind that day. I find it changes + - .2 mils in my limited experience.

Screenshot_20230518_110009_Strelok Pro.jpg


SmartSelect_20230518_105853_Strelok Pro.jpg
 
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I always consult a ballistics program when deciding where to zero my guns. I currently use chairgun. I know it was discontinued, I think that is better, I do not get annoying requests to update it. As an example of why I zero my P35s at 35 yards, I looked at what chairgun predicts for my P35-25 which likes H&N FTTs and shoots them about 860 fps. With a 35 yard zero, chairgun says I will be about .25 inches low at 20 and 40 yards. The only point I am above POA is at 30 yards where it says I will be .07 inches high. A little over 1/16th inch. If I ever get around to actually shooting FT I might regret this zero but I tend to think I will not. But it won't be with this gun so let's look at my P35-177. It likes Baracuda Match and shoots them at about 900 fps in warm weather, a little less when it's cooler. Chairgun says I will be exactly 1/16th inch high at 30. A little more than 1/4 low at 20 and just under 1/4 low at 40. I just don't think that 1/16th high at 30 will cost me. Someday I hope to find out. I am not trying to argue with Scott, I know he knows a TON more about FT than I do, I am trying to point out that a zero distance of around 35 yards with my guns puts me pretty close to the apex of the pellet's flight. I could switch the zero to 30 yards and be right at the apex according to chairgun on the P35-177.

With respect to having dope available, I put a little bit on a circular label I print on my laser printer and locate under the ocular lens cover. There is not enough room for what I would want for FT but for hunting or plinking, I can note the inches of holdover and the corresponding mil dots at 6X and 16X. I usually hunt at 6X. That way, I always have it with me.

I do not blindly trust chairgun, of course. I shoot targets at 5 yard intervals and compare my points of impact to what chairgun predicted. Sometimes I tweak the bc I used for the pellet (from hard air's article) to see if I can get a better match. But chairgun gives me a good guess at the pellet trajectory and a good starting point.
 
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I like this thread. it's pretty informative. I don't know much about the technical aspects and in-depth stuff and I have yet to use a ballistic app, but the instructions provided by @Xbowsniper in post #4 in the following thread are pretty simple to understand for finding your apex zero

Looking for post (apex zero)

I read a post about sighting your gun in for the apex of trajectory and now can’t find it. I’ve had no success with searching for it. Anyone have a clue?
www.airgunnation.com www.airgunnation.com

I think this may be a good starting point for a lot of the set-it-and-forget-it crowd. That's not to suggest that your zero shouldn't be checked or verified periodically. As a hunter I try to maintain a zero somewhere in the middle of my desired shooting range. Now I'm rethinking this after reading what @Motorhead said. I have noticed spots where my hold changes within this range and didn't know why. I have also noticed the need to check my zero after removing and replacing a scope and when seasons change. I've recently learned to review and verify my DOPE in accordance with my findings.
 
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Ezana4CE said:
I like this thread. it's pretty informative. I don't know much about the technical aspects and in-depth stuff and I have yet to use a ballistic app, but the instructions provided by @Xbowsniper in post #4 in the following thread are pretty simple to understand for finding your apex zero

Looking for post (apex zero)

I read a post about sighting your gun in for the apex of trajectory and now can’t find it. I’ve had no success with searching for it. Anyone have a clue?
www.airgunnation.com www.airgunnation.com

I think this may be a good starting point for a lot of the set-it-and-forget-it crowd. That's not to suggest that your zero shouldn't be checked or verified periodically. As a hunter I try to maintain a zero somewhere in the middle of my desired shooting range. I have noticed the need to check my zero after removing and replacing a scope and when seasons change. I've recently earned to review and verify my DOPE in accordance with my verification.
Click to expand...
Thanks!!!
Definitely worth trying 🤗🤙🎩
 
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I shoot every airgun I own using several pellet weights “at paper” and i map the trajectory from 10 yards to 100 yards. I then determine how far away the apex of the trajectory started and that’s where I zero my gun at, and how I make a dope chart for determining holdovers - I don’t do hold unders and don’t need to click. Most airgun pellets reach a flight apex between 18-25 yards. Depending on weight and speed. For good measure I also verify my results with StrelokPro
 
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