When taking a shot from approximately 20 feet above the ground, with a angle of 50 degrees, at 230 yards, using a 100 yard zero, will the shot impact about 1.5 inches low from point of aim? The ammo is Federal Gold Medal Match 168gr .308, assuming muzzle velocity of 2650fps, and a scope height of 1 1/4 to 1 ½ inches.
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Fieldcraft Elivated Shooting question
- Thread starter mb3
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Re: Elivated Shooting question
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MB</div><div class="ubbcode-body">When taking a shot from approximately 20 feet above the ground, with a angle of 50 degrees, at 230 yards, using a 100 yard zero, will the shot impact about 1.5 inches low from point of aim? The ammo is Federal Gold Medal Match 168gr .308, assuming muzzle velocity of 2650fps, and a scope height of 1 1/4 to 1 ½ inches. </div></div>
I'm slow, but I'm having trouble with those numbers, 20 feet above an 50* at 230 yds, what am I missing?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MB</div><div class="ubbcode-body">When taking a shot from approximately 20 feet above the ground, with a angle of 50 degrees, at 230 yards, using a 100 yard zero, will the shot impact about 1.5 inches low from point of aim? The ammo is Federal Gold Medal Match 168gr .308, assuming muzzle velocity of 2650fps, and a scope height of 1 1/4 to 1 ½ inches. </div></div>
I'm slow, but I'm having trouble with those numbers, 20 feet above an 50* at 230 yds, what am I missing?
Re: Elivated Shooting question
Actually, reading your question, I miscalculated. I calculated the amount the round would hit low if he had taken the angled shot with the correct dope for a flat 230 yard shot.
And since you asked, I'd like to know the reason for the question before I bother to calculate the correct answer.
Actually, reading your question, I miscalculated. I calculated the amount the round would hit low if he had taken the angled shot with the correct dope for a flat 230 yard shot.
And since you asked, I'd like to know the reason for the question before I bother to calculate the correct answer.
Re: Elivated Shooting question
Umm... maybe the shooting platform is twenty feet tall situated on the edge of a cliff face or really steep hill? I don't know.
Umm... maybe the shooting platform is twenty feet tall situated on the edge of a cliff face or really steep hill? I don't know.
Re: Elivated Shooting question
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MB</div><div class="ubbcode-body">When taking a shot from approximately 20 feet above the ground, with <span style="text-decoration: underline"><span style="font-weight: bold">a angle of 50 degrees, at 230 yards, using a 100 yard zero,</span></span> will the shot impact about 1.5 inches low from point of aim? The ammo is Federal Gold Medal Match 168gr .308, assuming muzzle velocity of 2650fps, and a scope height of 1 1/4 to 1 ½ inches. </div></div>
May be I am missing something here. As I understand it.
Zero range: 100 yards FLAT (This is my assumption, since it was not given)
Distance to target: 230 yards
Angle to target 50 degrees upward shot.
You dialed in the appropriate doping for a 230 yards based on your ballistic for the 168 grains at 2650 fps.
If all of those a correct, then I would say the shot will be high.
If you take the Cosine of 50 degrees, this gives you a value of 0.6427. Take that and multiply with your distance which is 230 yards. This gives a TRUE, HORIZONTAL range of 147.8 yards. So, if you dial your scope to 230 yards, you are going to be HIGH. That's why the saying is whether you shoot up or down, when unsure, aim LOW.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MB</div><div class="ubbcode-body">When taking a shot from approximately 20 feet above the ground, with <span style="text-decoration: underline"><span style="font-weight: bold">a angle of 50 degrees, at 230 yards, using a 100 yard zero,</span></span> will the shot impact about 1.5 inches low from point of aim? The ammo is Federal Gold Medal Match 168gr .308, assuming muzzle velocity of 2650fps, and a scope height of 1 1/4 to 1 ½ inches. </div></div>
May be I am missing something here. As I understand it.
Zero range: 100 yards FLAT (This is my assumption, since it was not given)
Distance to target: 230 yards
Angle to target 50 degrees upward shot.
You dialed in the appropriate doping for a 230 yards based on your ballistic for the 168 grains at 2650 fps.
If all of those a correct, then I would say the shot will be high.
If you take the Cosine of 50 degrees, this gives you a value of 0.6427. Take that and multiply with your distance which is 230 yards. This gives a TRUE, HORIZONTAL range of 147.8 yards. So, if you dial your scope to 230 yards, you are going to be HIGH. That's why the saying is whether you shoot up or down, when unsure, aim LOW.
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Re: Elivated Shooting question
If the total shot distance is 230yds at 50* no matter up or down,... the 20 foot above the ground would not matter at all. With only 150yds of grav working on the rd that was zero'ed at 100yds flat it would only be about 1" low,... depending on wind. That angle an more when shooting up or down, wind is different in the morn vs afternoon, but for a chip shot like that it won't make much of a diff. to a elevation change. Side wind at 230yd is still a number to look at.
If the total shot distance is 230yds at 50* no matter up or down,... the 20 foot above the ground would not matter at all. With only 150yds of grav working on the rd that was zero'ed at 100yds flat it would only be about 1" low,... depending on wind. That angle an more when shooting up or down, wind is different in the morn vs afternoon, but for a chip shot like that it won't make much of a diff. to a elevation change. Side wind at 230yd is still a number to look at.
Re: Elivated Shooting question
Respectfully disagree with you on that. The range is 230 yards, but with an inclination of 50 degrees, this makes the true range to be only 147.8 yards. Believe it or not, 50 degrees inclination is a lot. Of course, depending on the size of your target, hitting the side of a barn wouldn't matter much, but if you have to hit a 3" target at that range with the condition given, you would miss the target completely. Below is the JBM calculation for a 168 grains SMK using the G7 model calculation. Assuming again the MET and ENV factors are standard, the bullet drops 6.4 inches from a 100 yards zero by the it reaches 225 yards. This corresponds to a change of 2.7 MOA from zero. The table also calls for a drop of 1.4 inches and 0.9 MOA from a 100 yards zero for the same bullet. The difference is 5 inches in drop. Of course, we still have not consider the wind factor. Again, trying to hit a 3" target at 230 yards with a 50 degrees inclination, using a 230 yards doping (2.7 MOA), you would miss the target by 3.4" assuming if you are aiming at the center of mass of target.
Trajectory
Input Data
Manufacturer: Sierra Description: MatchKing™ (Litz)
Caliber: 0.308 in Weight: 168.0 gr
Muzzle Velocity: 2650.0 ft/s Distance to Chronograph: 10.0 ft
Sight Height: 1.50 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg
Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Round Output to Whole Numbers: No
Output Data
Elevation: 3.913 MOA Windage: 0.000 MOA
Atmospheric Density: 0.07647 lb/ft³ Speed of Sound: 1116.5 ft/s
Maximum PBR: 319 yd Maximum PBR Zero: 271 yd
Range of Maximum Height: 150 yd Energy at Maximum PBR: 1540.4 ft•lbs
Sectional Density: 0.253 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 2657.0 2.380 2633.1 0.000 0.0 ***
25 -0.6 -2.4 0.0 0.2 2604.6 2.333 2530.3 0.029 5.0 19.2
50 -0.1 -0.2 0.2 0.4 2552.8 2.286 2430.6 0.058 10.1 19.4
75 0.1 0.2 0.5 0.6 2501.5 2.241 2333.9 0.087 15.4 19.6
100 -0.0 -0.0 0.8 0.8 2450.8 2.195 2240.3 0.118 20.7 19.8
125 -0.5 -0.4 1.3 1.0 2400.7 2.150 2149.6 0.148 26.1 20.0
150 -1.4 -0.9 1.9 1.2 2351.2 2.106 2061.9 0.180 31.7 20.2
175 -2.6 -1.4 2.6 1.4 2302.3 2.062 1976.9 0.212 37.4 20.4
200 -4.3 -2.1 3.4 1.6 2254.0 2.019 1894.8 0.245 43.2 20.6
225 -6.4 -2.7 4.4 1.9 2206.3 1.976 1815.5 0.279 49.1 20.8
250 -8.9 -3.4 5.4 2.1 2159.2 1.934 1738.8 0.313 55.1 21.1
275 -12.0 -4.2 6.7 2.3 2112.7 1.892 1664.7 0.348 61.3 21.3
300 -15.5 -4.9 8.0 2.5 2066.8 1.851 1593.2 0.384 67.6 21.5
325 -19.5 -5.7 9.5 2.8 2021.4 1.811 1524.0 0.421 74.1 21.8
350 -24.0 -6.6 11.1 3.0 1976.6 1.770 1457.2 0.458 80.7 22.0
375 -29.1 -7.4 12.9 3.3 1932.3 1.731 1392.6 0.497 87.4 22.3
400 -34.8 -8.3 14.9 3.5 1888.5 1.691 1330.1 0.536 94.3 22.5
28/10/09 19:39, JBM/jbmtraj-5.0.cgi
Respectfully disagree with you on that. The range is 230 yards, but with an inclination of 50 degrees, this makes the true range to be only 147.8 yards. Believe it or not, 50 degrees inclination is a lot. Of course, depending on the size of your target, hitting the side of a barn wouldn't matter much, but if you have to hit a 3" target at that range with the condition given, you would miss the target completely. Below is the JBM calculation for a 168 grains SMK using the G7 model calculation. Assuming again the MET and ENV factors are standard, the bullet drops 6.4 inches from a 100 yards zero by the it reaches 225 yards. This corresponds to a change of 2.7 MOA from zero. The table also calls for a drop of 1.4 inches and 0.9 MOA from a 100 yards zero for the same bullet. The difference is 5 inches in drop. Of course, we still have not consider the wind factor. Again, trying to hit a 3" target at 230 yards with a 50 degrees inclination, using a 230 yards doping (2.7 MOA), you would miss the target by 3.4" assuming if you are aiming at the center of mass of target.
Trajectory
Input Data
Manufacturer: Sierra Description: MatchKing™ (Litz)
Caliber: 0.308 in Weight: 168.0 gr
Muzzle Velocity: 2650.0 ft/s Distance to Chronograph: 10.0 ft
Sight Height: 1.50 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg
Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Round Output to Whole Numbers: No
Output Data
Elevation: 3.913 MOA Windage: 0.000 MOA
Atmospheric Density: 0.07647 lb/ft³ Speed of Sound: 1116.5 ft/s
Maximum PBR: 319 yd Maximum PBR Zero: 271 yd
Range of Maximum Height: 150 yd Energy at Maximum PBR: 1540.4 ft•lbs
Sectional Density: 0.253 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 2657.0 2.380 2633.1 0.000 0.0 ***
25 -0.6 -2.4 0.0 0.2 2604.6 2.333 2530.3 0.029 5.0 19.2
50 -0.1 -0.2 0.2 0.4 2552.8 2.286 2430.6 0.058 10.1 19.4
75 0.1 0.2 0.5 0.6 2501.5 2.241 2333.9 0.087 15.4 19.6
100 -0.0 -0.0 0.8 0.8 2450.8 2.195 2240.3 0.118 20.7 19.8
125 -0.5 -0.4 1.3 1.0 2400.7 2.150 2149.6 0.148 26.1 20.0
150 -1.4 -0.9 1.9 1.2 2351.2 2.106 2061.9 0.180 31.7 20.2
175 -2.6 -1.4 2.6 1.4 2302.3 2.062 1976.9 0.212 37.4 20.4
200 -4.3 -2.1 3.4 1.6 2254.0 2.019 1894.8 0.245 43.2 20.6
225 -6.4 -2.7 4.4 1.9 2206.3 1.976 1815.5 0.279 49.1 20.8
250 -8.9 -3.4 5.4 2.1 2159.2 1.934 1738.8 0.313 55.1 21.1
275 -12.0 -4.2 6.7 2.3 2112.7 1.892 1664.7 0.348 61.3 21.3
300 -15.5 -4.9 8.0 2.5 2066.8 1.851 1593.2 0.384 67.6 21.5
325 -19.5 -5.7 9.5 2.8 2021.4 1.811 1524.0 0.421 74.1 21.8
350 -24.0 -6.6 11.1 3.0 1976.6 1.770 1457.2 0.458 80.7 22.0
375 -29.1 -7.4 12.9 3.3 1932.3 1.731 1392.6 0.497 87.4 22.3
400 -34.8 -8.3 14.9 3.5 1888.5 1.691 1330.1 0.536 94.3 22.5
28/10/09 19:39, JBM/jbmtraj-5.0.cgi
Re: Elivated Shooting question
I have to take the shot (or a similar one) in a competition and I have not been able to practice the shot prior to. So I am going in cold and I was trying to get the math straight. I am assuming the angle is going to be between 45 and 50 degrees. I took a similar shot many years ago and I believe I did not make any elevation adjustment (100 yard flat zero) and POI was a couple of inches low, which should be alright as the target is a 3 inch plate.
I have to take the shot (or a similar one) in a competition and I have not been able to practice the shot prior to. So I am going in cold and I was trying to get the math straight. I am assuming the angle is going to be between 45 and 50 degrees. I took a similar shot many years ago and I believe I did not make any elevation adjustment (100 yard flat zero) and POI was a couple of inches low, which should be alright as the target is a 3 inch plate.
Re: Elivated Shooting question
I just read some of the other posts and for clarification: the range from the target is 230 yards, the tower is approximately 20 feet off the ground, and the angle is down.
I just read some of the other posts and for clarification: the range from the target is 230 yards, the tower is approximately 20 feet off the ground, and the angle is down.
Re: Elivated Shooting question
OK - here's how to calculate an angled shot.
Inclined Fire Explained
In your case, simply use a ballistics program or other method to calculate the drop under the conditions you're in for a flat 230 yard shot. Then multiply the <span style="font-style: italic">dope</span> for that shot by the cosine of the angle. In this case, since that's 50 degrees, it's 0.64.
Example: My dope for a flat 230 yard shot in standard conditions is 3 minutes.
3 * 0.64 = 1.92
So, I'd dial up 2 MOA, and shoot.
OK - here's how to calculate an angled shot.
Inclined Fire Explained
In your case, simply use a ballistics program or other method to calculate the drop under the conditions you're in for a flat 230 yard shot. Then multiply the <span style="font-style: italic">dope</span> for that shot by the cosine of the angle. In this case, since that's 50 degrees, it's 0.64.
Example: My dope for a flat 230 yard shot in standard conditions is 3 minutes.
3 * 0.64 = 1.92
So, I'd dial up 2 MOA, and shoot.
Re: Elivated Shooting question
Lindy,
thanks for the example, it's a real help to me and clarifies several questions I had.
Lindy,
thanks for the example, it's a real help to me and clarifies several questions I had.
Re: Elivated Shooting question
You're quite welcome. I should add that under field conditions, a Mildot Master will not only measure the angle, but do the calculation, too.
You're quite welcome. I should add that under field conditions, a Mildot Master will not only measure the angle, but do the calculation, too.
Re: Elivated Shooting question
Lindy
Thank you for the info. That almost seems to easy. Regarding the Mildot Master, how does it help you to determine anlge?
Lindy
Thank you for the info. That almost seems to easy. Regarding the Mildot Master, how does it help you to determine anlge?
Re: Elivated Shooting question
You attach a weight on a piece of string to one corner. It has a scale on the back for measuring angles in 1 degree increments.
You attach a weight on a piece of string to one corner. It has a scale on the back for measuring angles in 1 degree increments.
Re: Elivated Shooting question
I have to get one of those. I calculated my drop and it came out to a little over six inches so I too would add in three mills. Since I don’t know the exact angle I used the cosine for 50 through 40 degrees and came up with: 1.92 mills through 2.2 mills. I am going to dial in 2 mills and let it fly, center mass on the plate. The good thing is a hit is a hit. Thank you for your help.
MB
I have to get one of those. I calculated my drop and it came out to a little over six inches so I too would add in three mills. Since I don’t know the exact angle I used the cosine for 50 through 40 degrees and came up with: 1.92 mills through 2.2 mills. I am going to dial in 2 mills and let it fly, center mass on the plate. The good thing is a hit is a hit. Thank you for your help.
MB
