How to compensate for 40 ft elevation drop?

This weekend I missed a shot on a nice 8 pt from 100 yards away. My rifle is zeroed at 100 yards and I am dead on when shooting from a flat horizontal distance. However, the shot I missed was from about 40 feet higher than where the buck was at my feeder. My blind is on a 10 ft tower that is on top of a ridge that is about 30 ft above the valley where my feeder is, so about 40 ft total elevation. According to google maps my feeder is about 100 yards away from my blind (point A to point B), though not accounting for the elevation drop. All of these distances are estimates, as I do not yet own a range finder.

I'm looking for advice on how to compensate for the drop in elevation. My scope is a Nikon Prostaff 3x9x50 BDC. My first thought is that I need to know what the exact distances are rather than going off of a map, so I'm looking to buy a rangefinder. I see that some rangefinders can calculate elevations. Before I go out and drop some money I wanted to see what advice you all might have for zeroing in my shot. Is there a specific rangefinder or other method I should be looking at?

Any help will be appreciated!

If you are 40 feet up and shooting from 100 yards away (300 feet), that puts you at an angle of a little over 7 degrees, which is 302 feet away. You would hold for a 302 foot shot, or just over 100 yards. Your zero would not change enough to matter. Something else caused the miss.

You need to be over 15 degrees to start to account for shot angle. And the further away you are, the more it effects the drop. Up or down does not matter, as they both provide the same amount of correction, if needed.

^^^ What he said

What Chad said. 100 yards would not make enough difference to notice.

With a rifle at that distance you do not need to adjust zero. If the feeder was 300 ft away and you are 40 feet above the target the bullet traveled 302 feet at an incline of approx 8 degrees. The difference in drop is negligible. Most likely you either A) missed or B) your scope is off or C) hit the deer such that the bullet went in at an angle and didn’t hit vitals or only one lung. You need to adjust point of aim rather than adjust your scope/zero

I agree with Chad - something else caused the miss. I had a buddy that wounded a few deer and missed some outright when hunting from a blind. He would nail bullseye when shooting from a bench, though.

Remember, those are two entirely different set ups! Most people practice from a bench, but never hunt from a bench!

So, I went and set up a target at 100 yards and made him shoot from the deer blind, so I could observe what was going on and see if I could help diagnose the issue(s). He was off by quite a bit.

I looked at how he was bracing his rifle on the window ledge and it seems like he didn't have very good control of the rifle.

When I shoot from inside a blind, I try to put the rifle against the corner of the window frame...so that the bottom of the stock is touching the frame, and the side of the rifle stock is touching the frame. With me holding steady, that's three points of contact. My buddy tried it, and BOOM! Bullseye! It's about having proper control and steadiness!

So, maybe go practice shooting from your blind and see how you can get better control of your rifle. See what feels best and figure out how you can get better control.

When I enter a new blind, I test how I will be able to get the best shot from each window from where I am sitting. I practice getting my rifle into the best positions, before I ever have to do it when I shoot.

The more you practice those types of things, the better you will be prepared on "game" day!


PS - also read an article once where an shooting instructor made his shooters run 100 yards to the bench where the rifle (already) was, and then try to hit bullseye. It was to mimic the adrenaline you get when an animal shows up that you are about to shoot. You have to learn to calm your body down, get your breathing under control and then control your rifle, accordingly. I thought that was a cool way to "practice" when buck fever hits!

I found this online to calculate for the distance. If you know the exact distance to the target in yards (Side C), you can work the problem backwards. What you have to account for in drop is the horizontal amount of bullet drop, not the actual distance to the target when shooting at an angle.

https://www.calculator.net/triangle-calculator.html

For example, if you have a shot angle of 10 degrees (up or down, it does not matter) and your laser distance is 400 yards (1200 feet). You would dial or hold for a 1181 feet, or 393 yards. You are calculating the amount of horizontal distance at 90 degrees for actual gravity drop of the bullet, not the actual distance to the target. So gravity only effects the bullet drop of 393 yards.

Now if you had the same lasered distance of 400 yards and 20 degrees, you would have 1127 feet to calculate for the drop, which is 375 yards. So a lasered reading of 400 yards away you would dial or hold for 375 yards. Again, you are calculating the amount of horizontal distance at 90 degrees for actual gravity drop of the bullet, not the actual distance to the target.

I believe some range finders Have two modes one for actual distance and if I remember right my vortex has an HCD? setting for "horizontal correct or compensated distance"? I just leave it on HCD as that is what I adjust by.

Tiger Valley has a 60 foot tower to shoot from. We have shot targets from straight down to out as far as about 400 or 600 yards from the top. Running an AR-15 in 223, the angle from about 50 yards was a slight hold low for a direct hit. Straight down, and I hold low about 4" to 6" low and it gets a hit from a rifle. At 200 yards and out, I would not hold any correction and just hold center for a hit.

https://tigervalley.smugmug.com/Tiger-Valley-Facility-Waco/Tiger-Valley-Facility/i-h8mCmQz/A

Bingo

Cut a board or use a shelf as an elbow brace.

My hog pen is about 55 yds from my blind which is also probably 40ft or so above the pen area. I have a 3rd profile on my Thermal I was going to use for a Subsonic profile for hogs during deer season with my RFB. If I did a 50 yd zero on flat land, I suppose things don't change any for the sub's as well given they're still flat to that far?

Blind elevation isn't a big deal for anything around 100 yards for most common deer rifles. Makes a much bigger difference when bow hunting an elevated position IMO

You have 40' of elevation with a line of site of 300'. This gives you a 7.67* angle. Take the cosine per angle and multiple by your line of site distance. That gives you the actual distance. In your case, that is just over 297 feet (99 yards).

Or IF he knows the horizontal distance (300 ft.) and the elevation (40 ft.) he can just use the common Pythagorean Theorem to attain the Hypotenuse (302.65' line of sight).

A^2+B^2=C^2
302.6 ft

^^^^^

Yep. Easy.

Practice at the range.

The golf range finders call it “slope,” which is illegal to use in PGA play. Some of them allow the user to turn that function off and just use it for distance. The slope function is what you’re talking about, and takes into consideration elevation and distance, to give you the true yardage.

Don't rest the barrel on the window, make sure to rest the stock not the barrel.

yep

You weren’t using Hornady BTHP Match bullets?

Winner chicken dinner.

The shooter needs to know the horizontal distance that effects the bullet path and make his dope for that distance 297 feet. Not the actual distance (Hypotenuse) 302 feet to target.

0.991053219 (Cos of 7.67) x 300 feet= 297 feet that gravity is effecting flight


https://www.rifleshootermag.com/editorial/hitting-a-high-or-low-angle-shot/83768

NRA Handbook
https://dailycaller.com/2014/04/03/how-to-shooting-uphill-and-down/