been doing alot of shooting at a buddy house who has his own personal range set up in back yard… pretty sweet. if you have ever seen a hickok45 video on youtube… its pretty much like his range. only problem is the range is on a hill. we are at the bottom, the further you shoot the further up the hill the targets are.
i just wanted to know what kind off effect does angel or grade have on my zero? if i am zeroed at 50, or 100 yards up on the hill… am i completely FUBAR at 50, or 100 yards on A FLAT range?
Great question. I’ve had the same question for both down hill and up hill shooting. I know that it is effected at some point, but I would like to know if there is a “data table” available or an equation that you would just plug in to get your desired results.
If you are zeroed at 100 and shoot uphill at 100, you will hit high.
Shooting Up or Down reduces the bullet drop. A slope doper is used for precision shooting to address this.
Example:
If you have a target at 100 yards and it’s a 45 degree up or down angle… the effective range is just over 70 yards.
Using the pathagorean theorem you can calculate the actual flat ground distance to the target and thus the distance that gravity will have an effect on your bullet.
Now within a short range like 100 yards this may be negligible. But if you get out far where the bullet is dropping at a faster rate… using actual distance with not dope sloping can make you miss the target big time.
kind of hard to believe but trajectory is only affected by the physical reduction of distance due to the angle and is not affected by whether going up or down hill.
that said, at ranges inside about 200 yards and any angle less than about 15% should be negligible within the shooter’s and gun’s spread of precision. after that there are apps on most any smartphone that can figure it out. I don’t have any on my iphone but I’ve been told that bulletcalc will work. good luck…
27deg is steep. Intermediate level downhill ski slope kind of steep. 5/12 roof pitch kind of steep. A normal household stair case is right at 32deg… Is that range actually that steep?
The big issue comes from true angle estimation. The overwhelming majority of shooters who don’t do much angle shooting calculate the actual angle as being far greater than it really is.
Gravity does not care if you are shooting up or down. The effect of gravity is constant. To calculate the distance use these numbers for cosine of angles…
Now you take your line of sight distance (LOS) x Cosine = Flat Range to target. The flat range to target is the actual distance that you will use to set your own dope or make your own adjustments. This assumes that you understand your adjustments on your rifle / load out to distance. So if your looking uphill or downhill and your target is say 500 yards away from your true LOS and your angle is 40* you should set your dope as if you were shooting on a flat range at 385 yards.
500yds x .77 = 385 yds. So your setting / hold off will be for a target at 385 yards and not 500 yards.
15* or less and it is almost meaningless for center of mass type of hits out until 300 yds or so.
awesome video. thank you!
so lets say my hill is a 20 degree hill and i want a 100 yard zero…
so 100y x 0.94 = 94y … i zero at 94 yards.
lets say i want a 50 yard zero
50y x 0.94 = 47 … i zero at 47 yards.
not a terable difference. thats good i was expecting much worse. and also after watching this video and paying attention to what he said about angles in nature…im probably working with 15 degrees. amazing the more i learn about this the less and less extreme of an angle my hill becomes
Guess I was typing when you posted this, but I checked out the video and said “Hey that’s Cleck”, lol. He is a really nice guy but a real geek when it comes to the techie side of things. That is not a bad thing either. I completed one of my sniper instructor certs at a place where he was an asst. instructor. If you ever run into him, ask him about his man on a bullet shifting gears analogy. We were drinking beers (a lot of them) and I did an impersonation of him using a beer bottle as the bullet. I’ll just say that his sense of humor needs some work.
Great guy though!
This is the big problem, being angle estimation. As you figured out, it really is less meaningful until distances start getting much farther out.
i know. i just a “man, i was waaay off” moment there. we only have access to 100 yards or so on this hill. i am just going to use the COS for 15 or 20 degrees and zero riffles at that distance on the hill… probably some where around 90 yards. i think for all intensive purposes it should come out to a true 100 yard zero.
I think you may have read that wrong… If you’re 100 yards straight line to the target, but it’s 20 Degrees up/down, you correct your dope for a 94 yard shot.
If you want a 100 yd zero and you put your target at 94 yards, you’re moving the target the wrong way… you’d need to push it out to about 104 yards.
