Hold over and under with 10 yard zero

How did you manage to get it zeroed at 10 yards? Open sights? If scoped, you will probably be hitting high at 15 to 20 yards with a 10 yard zero so you would probably have to hold under. I'd find a place to shoot to determine this and not rely on a "chart" or program but that's just me.

http://www.airguns.net/trajectory.php Enter your data in the appropriate boxes. Voila

This one is pretty good for airguns because it accepts intervals as small as one yard. You will need to know your pellet ballistic coefficient and your gun's velocity. If your pellet is the JSB 7.87, HAM reports the BC as 0.019. This is for the GA drag function, but the difference between GA and G1 will not matter for what you are trying to do.

http://www.shooterscalculator.com/ballistic-trajectory-chart.php

Far better to set up at the pellets natural APEX of flight ( generally for a low power gun @ 20-25 yards ) Then if your really close, shoot the prescribed HOLD OVER value for that distance.

Far better to set up at the pellets natural APEX of flight ( generally for a low power gun @ 20-25 yards ) Then if your really close, shoot the prescribed HOLD OVER value for that distance.

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I use near and far zero method instead of apex so we'll disagree on that bit but I think we basically see it the same. Zero at 10 yards would produce excessive rise above point of aim at "normal" shooting distances (20 out to maybe 30 yards). Plus it seems one would have to go well near maximum adjustment in elevation to reach such a close zero.

There is no right or wrong way to do these things, all I can do is tell you what I would do given your situation. As I understand it, you want to sight in at 10 yards in your basement, then be able to take game humanely from 10 to 20 yards. For hunting, I try to set up so that all I have to do is point and shoot at any distance I expect to encounter game (point blank range). For your gun and pellet choice, and assuming your scope setup is the same as on my R9, if you sight in 1/4" low at 10 yards, you will be within 1/4" from 10 yards to almost 30 yards. Although it would be better if you could just sight in at 25 yards, but as I understand it that is not possible right now. You really should evaluate your own setup using ballistic software of some kind, but this chart gives you the idea of what I am suggesting.







I suppose I should mention that to create this chart I did actually enter 25 yards as the zero distance, then just noted where you would have to zero at 10 yards to be on target at 25 yards.

As noted above, there is no right or wrong way to do this, only options. I prefer setting up as Michigander has noted, allowing some pellet rise above LOS but keeping it to an amount that allows exact "hold on" for the target size in question. To the OP, if you NEED to zero at 10 yards, some adjustable mounts like FX or Sportsmatch might allow less load on your scope. Not that any setup cannot work but there has been much discussion about the benefits in keeping the scope near its "optical center" and you probably could not do that at a 10 yard zero without such mounts, epsecially if there is any barrel droop at all. Different strokes.

Your hw50 should hit the apex at about 25 yards. That will be 4-7 moa ( about 1-2 mils) high at 25 with your current setting depending on scope height. If you are using a mil dot reticle, it should be easy to figure out. Scope height effects the difference more than velocity on the close side. Once the pellet starts to drop after the apex, velocity and ballistic coefficient take over. Play with chairgun some and see how the inputs affect the trajectory.

Assuming .177 with 800 fps you could use this 

I use the ChairGun app to play with different things. I don’t know how accurate the app is but it’s fun to play with. 

This can be done in about 5 minutes with just a couple of extra shots outdoors. Place a paper target at your 'other distance' (other than where zeroed), choose or make a mark for your point of aim (POA) and shoot once. Then look through your scope, set the cross hairs back at the POA. Look at the point of impact (POI) hole from the pellet you just shot, and match it up with the nearest hold point in your reticle, be it above or below the center cross hairs. That is your hold point for that range. Simple!

Depending on how consistent your gun shoots, this one-shot method will help you create a written 'range card' with hold points for all the strategic places in your yard, assuming a fixed shooting position. Keep your range card handy at your shooting location for instant reference. You can minimize attention from neighbors by test shooting just one new location per day for instance. The more shots you make, the more accurate your range card will be.

Regards,

Feinwerk

Duckfish & Feinwerk

Michigander said:

There is no right or wrong way to do these things, all I can do is tell you what I would do given your situation. As I understand it, you want to sight in at 10 yards in your basement, then be able to take game humanely from 10 to 20 yards. For hunting, I try to set up so that all I have to do is point and shoot at any distance I expect to encounter game (point blank range). For your gun and pellet choice, and assuming your scope setup is the same as on my R9, if you sight in 1/4" low at 10 yards, you will be within 1/4" from 10 yards to almost 30 yards. Although it would be better if you could just sight in at 25 yards, but as I understand it that is not possible right now. You really should evaluate your own setup using ballistic software of some kind, but this chart gives you the idea of what I am suggesting.



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I suppose I should mention that to create this chart I did actually enter 25 yards as the zero distance, then just noted where you would have to zero at 10 yards to be on target at 25 yards.

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if you sight in 1/4" low at 10 yards, you will be within 1/4" from 10 yards to almost 30 yards..
could you please clarify for me what you mean by "sight in 1/4" low at 10 yards". .how do I do that..thanks

bandg said:

I use near and far zero method instead of apex so we'll disagree on that bit but I think we basically see it the same. Zero at 10 yards would produce excessive rise above point of aim at "normal" shooting distances (20 out to maybe 30 yards). Plus it seems one would have to go well near maximum adjustment in elevation to reach such a close zero.

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so you would have to hold under in that situation..correct?

Since everyone is throwing their two cents in, I would like to mention Element Optics ballistic calculator phone app is an excellent resource.

Guest said:

I use the ChairGun app to play with different things. I don’t know how accurate the app is but it’s fun to play with.

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I use Chairgun as well its pretty accurate but using the right data is critical. Garbage in = Garbage out. You need the right scope height. Especially for near targets. The right velocity and BCs for further out. Unfortunately the provided BCs aren't always correct. BC changes with velocity and even between barrels.

Using two chronoraphs I've attained actual BCs and found that they didnt always match published BCs. Sometimes they were a little off, other times, they were a lot off.
For the OPs situation BC isn't really a factor.

I've always had more problems with very close targets. The concept of holding over for something eight yards away is unnatural for me. On the flip side using very close zeroes forces me to use hold under between the near and far zero which is even more unnatural.

You really need to find what works best for you. Chairgun is great but it's still best to set physical targets at various distances to see what you're actually dealing with.

Also keep in mind different pellets can throw you POI way way off and testing and zeroing will need to be done again.

Mycapt65 said:

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I've always had more problems with very close targets. The concept of holding over for something eight yards away is unnatural for me. On the

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Me too, but here's a trick that helps my brain: A commonly taught way to hold a gun is to keep the grip forefinger pointing straight until it is time to shoot, and then curl it to the trigger to release the shot. Think of that pointing finger as shooting at the target. When I do that and look through the scope, my brain "feels" the distance between the line of sight and the finger, and if I think of the finger shooting the target then it raises my aim naturally at close ranges.