You’ve probably read about the challenges of shooting from high angles. Tree stand or hillside, angle can affect your shot placement.
But how much? Nowadays, scoped long-range rifles and very good long-range hunting ammo are available to every hunter. But Ontario hunting is usually closer than 100 metres and no higher than a tree stand. How much does angle affect that?
There are lots of tools out there — laser rangefinders, ballistic apps, angle measuring devices, all intended to come up with an accurate solution. But let’s look at the challenge before we try to find a tool to help.
Up or downhill?
In the past, many people believed that when shooting uphill, your bullet would hit high and when shooting downhill, your bullet would hit low. That’s a myth.
In fact, your bullet hits high no matter whether the angle is up or down. There are physics to explain this, but a simple diagram will show it.
The key factor is this: the bullet is pulled by gravity for only the pure horizontal distance.
Imagine you are shooting upwards to your target. You range your target at 100 metres, but the horizontal distance is less. If the angle is about 25 degrees, for example, the horizontal distance is about 90 metres, and you wouldn’t change anything to make the shot.
So, how do you figure out the true horizontal distance? Well, there’s the math. Don’t stop reading. This is simple, you’ll see! If we’d been taught this stuff in school as “ballistics” instead of “math,” most of us would have been more interested.
You need an accurate measurement to the target (a laser rangefinder) and an accurate measurement of the angle from level. You need to have a tool to get that part right. Most of the students we’ve taught overestimate the distance and the angle.
The angle can be measured by a simple (usually free) phone app. Some rangefinders and rifle or scope-mounted devices also do this. Some of these tools will calculate the horizontal distance for you.
If you want to do the calculation yourself, all you need to do is take your angle and apply its cosine (see table, right) to your line-of-sight distance. A cosine is basically a percentage of the full value.
For example, if your target is at a 20-degree angle, multiply the line-of-sight distance by the cosine of 0.94 or 94%. If your target is 200 metres away, your horizontal distance is 188 metres. So, you’d set your elevation for 188 metres. This would be a long, steep shot for most Ontario hunters, and it would still only amount to less than 1⁄4 Minute of Angle (MOA) sight change.
You need both a long distance and a steep slope to make much difference on your bullet. In Ontario, you just don’t get these kinds of angles or distances. Even in mountainous areas, a really long shot would be 600 metres and an average angle might be 15 degrees from shooter to target (although there may be a gully in between), which would make 1⁄2 MOA difference. Best to set your elevation for the 600 metres and simply focus on making the best possible shot.
If you still feel spooked by angles, get yourself a rangefinder that calculates it for you. Then set your sight and shoot a good shot.
Originally published in the June 2021 issue of Ontario OUT of DOORS magazine.
Linda and Keith own and operate the MilCun Training Centre (www.milcun.com) near Haliburton, Ontario. They are the authors of the bestselling books The Wind Book for Rifle Shooters and The Secrets of Mental Marksmanship. Reach Linda or Keith at email@example.com.