I have been having a lot of issues with shot consistency and it was mentioned that it might have something to do with my target setup. Recently I have been shooting at a 6in/4in spinner that I have been sticking in the ground or stump, usually just below knee height and shooting from 25/30 ft. A guy I usually assume to be fairly knowledgeable said it is probably/possible because I am shooting at that extreme an angle and that I should only be shooting on a level plain?plane?. Will it really make that big a difference/effect on accuracy?
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Does shooting downward really make a difference?
- Thread starter iefstath
- Start date
Not at that distance.
yanici
NES Member
If you are having issues with consistency, then its a problem with you and not the target, stop flinching![[wink]](/xen/styles/default/xenforo/smilies.vb/002.gif "Wink [wink]")
Lotta truth in that statement. I know just what you mean.
![[smile]](/xen/styles/default/xenforo/smilies.vb/001.gif "Smile [smile]")
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The thing I find most challenging is unknown distance targets up/downhill. It makes a big difference but not at 25 yards. Sounds like a trigger/sight issue to me.
Just to illustrate the concept, you say your target is at knee height and 25 feet away. Let's assume you got that distance using a range finder from a standing shooting position. And also assume the distance from your knees to your eyes when standing is 4 feet. A target 25 feet from you (measured by line of sight) and 4 feet below you is at a -9.2 deg. angle (that's -.1607 radians) -- in real life you likely would just measure this angle directly.
So, if your line of sight distance is 25 feet and your angle is -9.2 deg. then what is the horizontal distance to target? It is 25 ft. * cosine(-9.2 deg.), or 25 * 0.98712 = 24.678 feet. The height of the target relative to your line of sight is 25 ft. * sine(-9.2 deg.), or 25 * -.1600 = -4 feet, which we already knew.
So, while your line of sight tells you that you are shooting at a target 25 feet away, the proper horizontal distance to use for calculating bullet drop during flight is 24.678 feet -- or just about 4 inches less. Clearly, the impact of gravity on bullet flight over 4 inches is trivial and can be ignored. And if it did matter we would need to know the length of your firearm and holding position in order to fine tune the proper answer.
In short, as EC noted, at the distance you are shooting it does not matter.
Even at 250 yards (as opposed to 25 feet), a down angle of 9.2 deg. only results in a distance adjustment down to 246.78 yards. Change that angle to 40 deg. (up or down, it doesn't matter) and then 250 yards line of sight is only 192 yards of horizontal travel.
So, if your line of sight distance is 25 feet and your angle is -9.2 deg. then what is the horizontal distance to target? It is 25 ft. * cosine(-9.2 deg.), or 25 * 0.98712 = 24.678 feet. The height of the target relative to your line of sight is 25 ft. * sine(-9.2 deg.), or 25 * -.1600 = -4 feet, which we already knew.
So, while your line of sight tells you that you are shooting at a target 25 feet away, the proper horizontal distance to use for calculating bullet drop during flight is 24.678 feet -- or just about 4 inches less. Clearly, the impact of gravity on bullet flight over 4 inches is trivial and can be ignored. And if it did matter we would need to know the length of your firearm and holding position in order to fine tune the proper answer.
In short, as EC noted, at the distance you are shooting it does not matter.
Even at 250 yards (as opposed to 25 feet), a down angle of 9.2 deg. only results in a distance adjustment down to 246.78 yards. Change that angle to 40 deg. (up or down, it doesn't matter) and then 250 yards line of sight is only 192 yards of horizontal travel.
economist, I don't think it's that simple. I think you also need to take in to account the vertical and horizontal components of the bullet velocity. Remember that barrels are angled slightly upward, so the parabolic trajectory of the bullet crosses the sights twice, once going up and once going down. I'll do some math later, but I don't have time at the moment.
ETA: I'm talking about the 250 yard case. I agree with everyone who's said it doesn't matter a bit at 25 feet.
ETA: I'm talking about the 250 yard case. I agree with everyone who's said it doesn't matter a bit at 25 feet.
Absolutely, engaging a target at an angle is more complex than just getting the horizontal distance. Flight time is the most important secondary factory (an angled shot at a given horizontal distance has a different flight time, and different gravity impact, than a horizontal shot at the same horizontal distance).
