Rifle angle shooting

[sand rat]

Hi I'm new here, and I have a question.

I'm going to go shoot at a range that has targets to 1300 yards. I will be firing form a hill, shooting across a valley that slopes upwards but the targets are still at a slightly downward angle form 90deg. straight line of sight. The targets are at known ranges. 300 to 1300 yards.

My question is when do I take my cosine angle on my rifle. Do I take it with the scope set on my 100yrd zero for each and every target. Or like if I'm shooting the 1000 yrd target do I put the 32 moa in the scope and then take the cosine angle, to get the actual moa to the target.

I'm asking this because observing other shooters at that range, when at the longer ranges after they have dialed in the moa in their scopes for the longer shots the rifle is now at an upwards angel form horizontal to compensate for the bullet drop.

So do I take a cosine angle for each and every target with the scope at my zero range, or after I have clicked in my moa for the appropriate target, then take the cosine angle for each target.

sand rat

 

[TiroFijo]

Re: Rifle angle shooting

For a 1000 yds shot you have less than 40 MOA from your 100 yds zero, and this is only 2/3 of a degree. Don't worry about it.

Check this

http://www.exteriorballistics.com/ebexplained/article1.html

 

[kraigWY]

Re: Rifle angle shooting

Its easier for me to forget the rifle, get the angle, then the cosine. Get the range to the target, multiply that times the consine to get your actual or flat range to adjust for.

I'll add this. I'm old school. We didn't have fancy range finders, mil dots and such. I like teaching ranging with a map and compass or protector. Your maps have grid lines showing elevation changes but the map is flat. If you use your protractor (or compass) to get the range, that range is flat. You can disregard any angle adjustments.

I do the same thing in LE Sniping/Sniper instructing. Cops tend to get steeper angles because they tend to go to roof tops and shoot down.

You can go to the county or city and get "to scale" plot maps of your area of concern. Using the scale you can plot the "flat" distance from building top to the ground at two or three blocks and disgard your angle computions.

But I degress, no one uses maps any more, every thing is electronics.

 

[sand rat]

Re: Rifle angle shooting

Thanks for the help.

sand rat

 

[doc76251]

Re: Rifle angle shooting

Using cosine and such is for when you change angles AFTER you have a zero.

Less than 10* of angle is negligible and the difference that is there is usually lost in the shooter/ammo/rifle accuracy white noise.

Don't over think it.

Cheers,

Doc

 

[azwolf1500]

Re: Rifle angle shooting

I can't see any range that far screwing people on the "known" distance if the angles are extreme. As long as you have your correct dope set for the distance shoot it. If its off then check your angle and get the correction. Do you have verified dope for all distances you are planning on shooting? Ballistic calculators don't count... you need to verify them for each rifle/load combo with the effects of the elements! I've kept dope books since I was trained so many years ago.

 

[Sharpsman]

Re: Rifle angle shooting

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">Its easier for me to forget the rifle, get the angle, then the cosine. Get the range to the target, multiply that times the consine to get your actual or flat range to adjust for.

I'll add this. I'm old school. We didn't have fancy range finders, mil dots and such. I like teaching ranging with a map and compass or protector. Your maps have grid lines showing elevation changes but the map is flat. If you use your protractor (or compass) to get the range, that range is flat. You can disregard any angle adjustments.

I do the same thing in LE Sniping/Sniper instructing. Cops tend to get steeper angles because they tend to go to roof tops and shoot down.

You can go to the county or city and get "to scale" plot maps of your area of concern. Using the scale you can plot the "flat" distance from building top to the ground at two or three blocks and disgard your angle computions.

But I degress, no one uses maps any more, every thing is electronics. </div></div>

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