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I always hold lower either up hill or down hill as gravity has less of an influence.
A mil-dot master has the adjustments for slope.
A mil-dot master has the adjustments for slope.
Upslope/Downslope Terrain Adjustment
Paper punching at great distances from a bench is challenging and addictive! But in the field, be it combat sniping, or hunting, up slope and down slope shots are often necessary. Is there some sort of chart or scale of elevation adjustment for various slopes?
There seems to be profuse data on every other aspect of shooting sports, so I am hoping there is some info on this issue.
Thanks.
There seems to be profuse data on every other aspect of shooting sports, so I am hoping there is some info on this issue.
Thanks.
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Check out this site. the user can input data and learn a lot!!
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
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From what I understand of shooting up or down hill's is you have to take into consideration the horizontal distance not the vertical distance. For example, if you are shooting down a hill at a target that is 300 yards away down the slope, but is only 50 yards out on the horizontal, then your target is basically 50 yards away. That's how it was explained to me once, don't know if it's gospel or not.
Bob
Bob
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yes depending on the slope. you need a cosine or degree indicator and a calculator to get it correct. unless youre a math nerd. lol
you can also use a mildot master and many range finders provide the slope in degrees.
say you range something at 450 yards at a 38 degree angle. you take the 38 and punch it into your calculator and press the cos button and you get .78. then multiply by the yards (450) and it comes up with the corrected range which is 351.
so cos x range = corrected range.
its the same up or down hills.
you can also use a mildot master and many range finders provide the slope in degrees.
say you range something at 450 yards at a 38 degree angle. you take the 38 and punch it into your calculator and press the cos button and you get .78. then multiply by the yards (450) and it comes up with the corrected range which is 351.
so cos x range = corrected range.
its the same up or down hills.
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or one can use a ballistic app like "Strelok" on their smartphone as well.
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Field shooting doesn't always give you time for apps, rangefinders etc. The above is right, its however far the target is if you draw a right angle horizontal from you, vertical from the target. Its the horizontal distance that matters. So the quck n dirty rule for up or down hill is aim low!
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For hunting shots when I don't have time to figure dope and adjust the turrets, I just hold low for both up or down hill shots.
This is a good read on the subject from Major John Plaster, http://millettsights.com/downloads/ShootingUphillAndDownhill.pdf
As others have pointed out, a Mill Dot Master makes quick work for dope on elevation shots, an angle cosine indicator is also handy
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There are cheaper, but just as effective, tools available to measure shooting angle
The Scope Doper
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THLR's Rangecard is small and packed with info., I have one
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This is a good read on the subject from Major John Plaster, http://millettsights.com/downloads/ShootingUphillAndDownhill.pdf
As others have pointed out, a Mill Dot Master makes quick work for dope on elevation shots, an angle cosine indicator is also handy
There are cheaper, but just as effective, tools available to measure shooting angle
The Scope Doper
THLR's Rangecard is small and packed with info., I have one
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363 Posts
Hah.... Good laugh.
Most newer rangefinders will give you not only the angle, but you can select for actual range or ballistic range. For dummies like me who neither have the time or mental prowess to do mathematical equations in the field it works pretty slick.
I always have it set for ballistic range(all I care about).
Or like others have said aim low, uphill or downhill.
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I love it ! a question not often asked, and a really good one at that . thanks Happy Trails.
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Thanks much. I knew you guys would have a ready and helpful answer. For some reason I though it was aim high for one and aim low for the other, but I couldn't remember. Now I know: Aim low for either! I will play around with that out in the field on familiar terrain and see what works out.
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Doesn't really matter until you get upwards of about 20 degrees.
For angles above 40 deg, the sinX = (X+25)/100
Angles less then/equal 40, sinX = X/60
And cos x = sin(90-x).
So for a 20deg slope, I take the sin (90-20) = sin70 = 70+25 = 95%. That's the factor you correct your range with.
at a 50deg slope, sin (90-50) = sin40 = 40/60=2/3
For angles above 40 deg, the sinX = (X+25)/100
Angles less then/equal 40, sinX = X/60
And cos x = sin(90-x).
So for a 20deg slope, I take the sin (90-20) = sin70 = 70+25 = 95%. That's the factor you correct your range with.
at a 50deg slope, sin (90-50) = sin40 = 40/60=2/3
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This one is much easier to use...
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Basically, it minimizes your math. If you're at zero, then you range at 100% distance. So for example, you're ranging a target at 1,000 yards and the cosine indicator says 82. That's 82% of your actual distance that you set your elevation for; or adjust your scope for 820 yards.
Now for deer hunting applications with a 200yd zero, then a center hold will keep your shot placement in the kill zone within 100 to 300 yards at nearly any angle.
Tony.
Basically, it minimizes your math. If you're at zero, then you range at 100% distance. So for example, you're ranging a target at 1,000 yards and the cosine indicator says 82. That's 82% of your actual distance that you set your elevation for; or adjust your scope for 820 yards.
Now for deer hunting applications with a 200yd zero, then a center hold will keep your shot placement in the kill zone within 100 to 300 yards at nearly any angle.
Tony.
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