On flat ground, like at the archery range, it’s pretty simple to hit your target. You find the distance, draw to your anchor points, put the pin on the bull’s eye, and release.

It’s natural. You sight in your bow on a horizontal plane, so your pins are set for horizontal distances. If your form is good, you make a perfect “T” with your body: your torso perpendicular to the ground, and your arms perpendicular to your torso.

But now it’s hunting season, and you’ve got a muley wearing a chandelier on his head, quartering away just up the hill. It’s very steep, but you don’t know the angle. Your rangefinder says he’s at 41 yards. Your nerves are firing, and if you’ve only been practicing on flat ground, you’re instinct will be to draw, raise your bow arm until the 40-yard pin lines up on his vitals, and release. 

And more than likely, you'll send your arrow high over his back, maybe into the next drainage. Or worse, if your bow is particularly flat shooting, you might just spine him.

“The reason I know how it’s done is from epic failures just like that,” says Sitka Ambassador Shaun Mathewson. “I’ve missed big on some really big deer.” 

The good news, he says, is that with knowledge and practice, you can be as accurate shooting on slopes as you are on the range. You just need to do three extra things:

1.) Measure the angle of the hill

2.) Calculate the horizontal distance

3.) Dial in your shooting position

To understand how slope affects your shot distance, think of the right triangles you learned about in geometry.

If you're standing at point A and the deer is at point B, your rangefinder will give you the straight line distance, labeled c. 

However, your arrow will only travel a horizontal distance of b, which is much shorter. That distance determines the yardage pin that you'll want to use. As you can see, the horizontal distance will always be shorter, whether your target is uphill or downhill from you.

Measure the angle of the hill

Many companies make angle-compensating rangefinders, but Shaun doesn't trust them, saying that none of the elite shooters that have trained and mentored him use them.

"I'm not sure the technology is quite there yet to really depend on them," he says.

So he measures the angle of the shot using a low-tech, old sniper tool called a Slope Doper. He simply eyes down the top of the card to his target and then holds the needle in place to read the angle. 

“Very seldom will the slope be as steep as you think it is,” Shaun says.

Calculate the horizontal distance

The Slope Doper has conversions printed next to the angle to aid with calculations, but in a hunting situation, Shaun says he doesn't have the time to do the math. Instead, he's printed out an archery cut chart and taped it to the back of the Slope Doper for quick reference.

Archery cut charts vary slightly for uphill shots and downhill shots, as the arrow loses some energy as it fights gravity, and gains a little as it works with gravity. The above chart is for shooting uphill, though the adjustment for shooting downhill is slight. For example, a downhill shot at 60 yards and 45 degrees, would call for sighting at 41.4 yards, versus the 43.6 yards on the uphill chart. Most hunters, given either of these distances, will hold directly on their 40 yard pin. 

There are also very slight variations for speed. The above cut chart is optimized for 280 fps.

It might sound a little complicated, but Shaun says the process becomes very quick and easy with practice. Sighting down the card, reading the angle, and flipping over for the chart takes only a few seconds.

"It becomes second nature. What really messes people up is when they alter their shooting form," he says.

Dial in your shooting position

On hills, many hunters have a tendency to change their position, dropping their arm at the shoulder for a downhill shot, or raising it for an uphill shot. The change in angle causes them to heel or palm the bow – which puts upward or downward torque on the riser – and ultimately, they throw the shot.

Beyond torque, changing the angle of the bow arm changes the distance and the angle from a shooter’s anchor points, further throwing off the aim.

If you’re aim is off and you throw the shot, you’re lucky to put the arrow in the same postal code as your quarry’s vitals.

The solution, Shaun says, is to bend at the waist and knees to set the shot angle, while keeping that perfect “T” shape between your arms and torso. That way, your release position is the same in the field as it is on the range.

"Like I said, I'm not a great shot like some of the guys out there," he says. "But I have learned from guys who are. If you can do these things and get out of the bow's way and just let it do what it's designed to do, you're shots are going to be a lot more accurate in the field."

So how about you: Have you had some "epic failures" like Shaun? How do you set up for shots on a slope?