Rule of Thumb for Shooting Down Hill

[MagnumManiac]

Rule of thumb for uphill or downhill shots is to aim in the bottom third of HAIR. Never aim for AIR.
Unless the shot is almost vertically up or down, you always aim LOW.
I lost an animal due to not aiming low enough because in my haste I forgot to aim low. Animal was taken some months later and the hit that didn't take him had healed over. Was hit between the shoulder and spine without doing any real damage. Was a Nosler 225g Accubond out of a 338WM at roughly 225mtrs.

Cheers.

 

[Reelamin]

I shot a bull two years ago at 520yds at a 18 percent angle. I hit a little lower than expected and it still dropped in about five steps. I held low expecting it to climb more than it did. When I ran a program at home and compared to where I held I estimate the hit it was off by about 2-3 inches. Factoring in accuracy potential and the situation....I was off just a curly one on my hold. I just ran the JB Ballistics with that load and rifle and it showed less drop of 1" using my hunting rifle zero (380 yards) in a perfect world. I'm having a hard time believing the difference at 500yds with a 10 degree is 100yds different dope. I have been wrong before and I am open to learning the facts.

 

[Rhovee]

I don't worry about it with a range finder that figure the angle out and outputs the range you need to dial for.

 

[Reelamin]

I don't worry about it with a range finder that figure the angle out and outputs the range you need to dial for.

I have a Leica B model, and have never ever used the internal ballistics. Nope no chip ever even put in it. Last year I shot a bull at 650yds uphill at a 28 degree angle. Standing perfectly broadside. Dialed exact yardage held right on his brisket and let her go. He spun around to go back because he could not go forward and stumbled a few steps going down hill and flopped over. This was the first time I ever really was a little nervous on the hold, and before I hunt this area again I will have my range finder with the ballistics in it finally. Didn't like being even a little nervous on my dope/hold.

 

[wolffo]

correct
the "horizontal distance" of an angled shot is shorter for both up/down hill
the old mildot master comes with a booklet describes this and a feature to estimate angle
no batteries required

 

[snowghost51]

I don't know a rule of thumb or formula but angles up or down will result in a high hit,If you know the cosine angle most apps would correct for that

Use cosine to determine horizontal distance.

 

[Reelamin]

That's what I did to come up with only a 8 yard difference.

 

[Critter Picker]

What we use for a rule of thumb in archery is aim the horizontal distance. It's probably not perfect but it will keep you in the 12 ring. I would think it would get you really close with a gun also.

 

[Mike Matteson]

The greater the angle the more you have to change your aim. (Same Hold Up or Down Angle) Your bullet is going in a arc, while you are looking vertical line. So your bullet is flying high no matter if shooting up hill or down hill. They make range finders that will give you the info. I product a shooting print out that I tape to my rifle stock at gives me holds and wind draft figures. You are not the only person that has done this. In my younger days I was shooting at a deer at somewhere around 600yds. Down hill angle somewhere around 20-30%. I held over and the bullet went over his back by several inches. Shot 3 times and still over. I could see where the bullet was hitting. I couldn't believe it at the time. It was a standing shot for me. My line was dead on, but over. After getting back I pull out my Sierra Manual and looked it up. and learned. That was in the middle 70's, when we didn't have all the equipment at that time. Best go out and set up targets at different elevation or angle at longer yards to just to see how you bullet travels.

 

[johnish]

Hi everyone. Got back earlier this week from hunting CO 2nd rifle elk season in GMU 681. Took a cow early on but the bulls were scarce especially given the high winds. At dusk on Weds I had a 5 pt bull appear at 503 yards quartering to and since he was close (30 yds from) a fence (private ranch on the other side), I aimed high on the shoulder (after dialing my Gunwerks 7mm RM shooting 168 gr VLDs to 500 yds) & gently squeezed. My spotter called the shot right over his back. The bull promptly moved off into the timber (not presenting another shot), jumped the fence and minutes later was shot on that private ranch. One more data point, the bull was 10 degrees downhill from me and I had a solid but not perfect rest.

My question is, did I just muff the shot high or should I have dialed a shorter distance on the Viper PST? Do you have a rule of thumb for shooting at high or low angles, like "for 10 degrees, reduce the distance by 10%"?
Thanks for your time & advice!

The best way to gain 'experience' of this effect is with an air rifle. With an air rifle (with a legal UK limit of 12 ft/lbs) a 50 yard shot is a long one with a lot of drop. Take that same shot up into the trees and the amount of drop reduces drastically. You learn quickly to compensate when hunting squirrels or pigeons.
It is all about the physics of the gravitational (G) impact of the projectile. When the shot is flat the G impact is 100%. Shooting at an angle reduces this because the force is being applied at an angle rather than perpendicular.
The 'Aim low' rule of thumb is not a bad one!
If you are taking a lot of shots up and down steep slopes getting an angle cosine indicator is a good idea. Or just get a range finder with one built in...

 

[Reelamin]

What we use for a rule of thumb in archery is aim the horizontal distance. It's probably not perfect but it will keep you in the 12 ring. I would think it would get you really close with a gun also.

Seems odd since bow sights are above the bore/arrow, and the arrow must fly in the same arc pattern to get to the POI. Gravity still applies to an arrow as it does to a bullet. I'm open to learning more if you have the information. I don't shoot a very fast bow 274fps, and mine has always shot noticeably higher at angles above 15 degrees. I dont remember checked the degrees just estimating now, and when I did the testing its very close to a 30 degree angle. It is 5 yards different hold at 40-60 yards.

 

[ecooper1514]

Sometimes chicken….sometimes chicken feathers. My guide told me this when I wounded a leopard at 100yrd steep downhill shot. It happens.

 

[Stgraves260]

Hi everyone. Got back earlier this week from hunting CO 2nd rifle elk season in GMU 681. Took a cow early on but the bulls were scarce especially given the high winds. At dusk on Weds I had a 5 pt bull appear at 503 yards quartering to and since he was close (30 yds from) a fence (private ranch on the other side), I aimed high on the shoulder (after dialing my Gunwerks 7mm RM shooting 168 gr VLDs to 500 yds) & gently squeezed. My spotter called the shot right over his back. The bull promptly moved off into the timber (not presenting another shot), jumped the fence and minutes later was shot on that private ranch. One more data point, the bull was 10 degrees downhill from me and I had a solid but not perfect rest.

My question is, did I just muff the shot high or should I have dialed a shorter distance on the Viper PST? Do you have a rule of thumb for shooting at high or low angles, like "for 10 degrees, reduce the distance by 10%"?
Thanks for your time & advice!

See if this helps. This what I use on my measured straight LOS shots. Convert your angle to cosine so you can easily do the math.

 

[Reelamin]

@Stgraves260
What does your math show he should have dialed for to be exact? Is it not multiply the yardage by the cosine? If I am correct the yardage hold should have been 495yards or in his instance exactly what he dialed.