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Do small changes in elevation affect POI?

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PseudoSane:

--- Quote from: customcutter on April 17, 2022, 09:58:27 AM ---Absolutely, I remember years ago shooting archery, I could be zeroed at 20yds.  If I went up a tree stand 10-15 feet, I was no longer zeroed.  They actually made sighting pins that would swivel based on the angle you were shooting to compensate for the change.

As others have mentioned Ballistic Calculators can calculate the change for you.

--- End quote ---

Thanks all, I'll give those apps a try!

ac12:

--- Quote from: PseudoSane on April 16, 2022, 07:16:43 PM ---I was messing around with my Avenger .22 with some JSB 15.89gr this weekend. I zeroed it at 30 yards (doing 850 fps), and noticed that when I switched to a target at 50 yards I had a 1 inch drop in POI. Would a 1 inch drop between 30 and 50 yards be expected? 

I would mention that I'm shooting down from my deck which is about 10 ft above the ground. Where the range is setup there is a slight increase in elevation so that the 30 yard target is about 2-3 feet lower than the 50 yard target. Could this slight increase in elevation in the 50 yard target account for the POI change? And, could the fact I'm shooting slightly angled down be contributing?  Thanks!

--- End quote ---

The 2 to 3 foot elevation change theoretically changes the zero.  But in practice, 2 to 3 feet is so little, that I doubt it makes much difference.

BUT, the distance change from 30 to 50 yards WILL make a difference.
The pellet travels in an arc, NOT straight like a laser.  So a rifle zeroed at X yards will either be traveling on the upward or downward part of the arc at a different range.

mwgm2020:

--- Quote from: DMR214 on April 16, 2022, 09:12:23 PM ---I have a 30 yard zero with the .25cal going 866fps /.046bc. At 50 yards It drops 1.6", when I shoot out the upstairs window at 50 yards there's no difference in hold. That's 15ft above the target.

--- End quote ---
Here is a quick Chairgun graph with the information you gave, using a one inch KZ.  This does not include the inclines.

mwgm2020:
BTW, you might want to change your zero settings to Chairgun's calculated best zero, for 1 inch KZ of 16 yards near and 39 yards far.  Here is the graph.

PseudoSane:

--- Quote from: mwgm2020 on April 17, 2022, 05:20:47 PM ---BTW, you might want to change your zero settings to Chairgun's calculated best zero, for 1 inch KZ of 16 yards near and 39 yards far.  Here is the graph.

--- End quote ---

That's super helpful, thanks!

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