Range Report ELD-M 130 gr real BC?

[TRAC]

Here are the results of my test this morning.
Temp 30 degrees F
Humidity 27 %
Station pressure 27.2 inhg
Wind was 9 MPH from 10:30

Checked velocity with magneto speed and average was 2905 FPS with an SD of 7 and ES of 20.

Verified zero at 100 yards.

Ranged target with 2 separate Leica rangefinders at 1,314 yards. Target was a nearly vertical rock face with clay pigeons stuck on it. This makes it very easy to spot exact impact points. There was less than 1 degree vertical angle of our shots with us lower than the targets.

Shot over 20 shots at 1,314 and my dope was very consistent hits at 12.6 mils elevation. Scope is a Kahles 624i gen 3 and tracking is very good.

We then moved to 984 yards and shot the same targets and my dope was very consistent hits at 7.5 mils elevation.

With all environmental data correct in Strelok and all other inputs correct the closest G1 B.C. that produces these drop numbers is .615.

Please check my numbers and make sure I have not missed a variable.

According to my simulation on your data BC G1 is 0.579 .
Can be a slightly difference because of scope height (I didn't know yours, I input 4.5 cm (1.77 in) as scope height.
4.51 % difference compared with Hornady published data.

I tested this 0.579 BC with Strelock, JMB and Applied Ballistics and is spot on with your data (12.6 MIL at 1200 m and 7.5 MIL at 900 m)

 

[Mordamer]

According to my simulation on your data BC G1 is 0.579 .
Can be a slightly difference because of scope height (I didn't know yours, I input 4.5 cm (1.77 in) as scope height.
4.51 % difference compared with Hornady published data.

I tested this 0.579 BC with Strelock, JMB and Applied Ballistics and is spot on with your data (12.6 MIL at 1200 m and 7.5 MIL at 900 m)

I just rechecked everything in my Strelok and I still get a .62 with my variables. Not sure what the disconnect is between our calculators. Maybe something on environmental data. In Hornady's app I also get a B.C. over .6 with my same data.

 

[TRAC]

I just rechecked everything in my Strelok and I still get a .62 with my variables. Not sure what the disconnect is between our calculators. Maybe something on environmental data. In Hornady's app I also get a B.C. over .6 with my same data.

I checked again I got slightly different results .

Input data:

JMB results:

Strelock

Applied Ballistic

TRASOL

So I got using your data (using as precise as was possible decimal data, seems stupid but I tried to be as close as possible to your data):
0.578 in JMB (metric)
0.577 in JMB (imperial)
0.590 in Strelock Pro
0.580 in Applied Ballistic
0.613 in Trasol
____________________
Average BC 0.588 G1
If I consider Trasol data as outlier I get an average of 0.581 G1.
This is what I can do, maybe someone with more experience in such things can more accurate results.
Please check the results...cam be wrong if i screwed something

 

[TRAC]

Also checked in Quicktarget ...odd again, here I got 0.62 BC.
Hornady in apparence did a very good job

Bullet Type : .264, 130, Hornady ELD-M 26177
Bullet Weight : 130 grains or 8.42 Grams
Muzzle Velocity : 885 m/s
Twist Length : 279.4 mm (RH)
Gyro. Stability : 1.02
Crosswind Speed : 4.0 m/s
Ballistic Coefficient(s) (G1) :
C1_1=0.620@V>0 m/s;


Optimum trajectory information :
Optimum sight-in range (X) = 185 m
with max. ordinate above LOS at range (M)= 111 m
and max. point blank range (P)= 214 m.
-------------------------------------------------------------------------------------
Sight-in clicks, 1 click = 0.915 cm/100 yd. or 0.36 in/100 yd.
Height of sight above bore axis = 4.496 cm or 1.77 inch
Gun is zeroed-in at 91 m,
by sighting-in at level firing
Note: Sight-in atmosphere differs from atmosphere for table
ZeroRange - Air Density : 1.1789 kg/m³
-------------------------------------------------------------------------------------
Range Velo Time of Energy Path Spin / Wind- Total Sight correction Target
city flight to dage, Wind drop for setting new lead
LOS of 4.0 m/s zero range 10 m/s
-------------------------------------------------------------------------------------
·Meter m/s s Joule cm cm MOA cm Clicks MOA m ·
-------------------------------------------------------------------------------------
| 0 885 0.0000 3301 -4.5 0.0 ----- 0.0 ------ ----- 0.00
M 81 845 0.0940 3003 0.0 -0.6 -0.26 4.3 0.0 0.00 0.94
X 91 840 0.1059 2968 -0.1 -0.8 -0.29 5.4 +0.1 +0.02 1.06
| 100 835 0.1167 2937 -0.3 -0.9 -0.32 6.6 +0.2 +0.08 1.17
P 155 808 0.1840 2751 -3.9 -2.2 -0.49 16.1 +2.5 +0.85 1.84
| 200 787 0.2405 2607 -10.2 -3.6 -0.62 27.3 +5.1 +1.74 2.40
| 300 740 0.3706 2306 -35.7 -7.9 -0.90 63.5 +11.8 +4.07 3.71
| 400 695 0.5102 2033 -79.3 -14.6 -1.25 117.9 +19.8 +6.80 5.10
| 500 651 0.6594 1787 -143.6 -23.7 -1.63 193.0 +28.7 +9.86 6.59
| 600 610 0.8174 1564 -230.3 -34.9 -2.00 290.4 +38.3 +13.18 8.17
| 700 569 0.9856 1363 -342.4 -48.6 -2.39 413.3 +48.8 +16.80 9.86
| 800 531 1.1696 1185 -488.2 -66.3 -2.85 569.8 +60.9 +20.96 11.70
| 900 494 1.3668 1029 -669.9 -87.2 -3.33 762.2 +74.3 +25.57 13.67
| 1000 460 1.5754 890 -888.8 -110.7 -3.81 991.9 +88.8 +30.54 15.75
| 1100 428 1.7997 772 -1155.2 -137.9 -4.31 1269.1 +104.9 +36.08 18.00
| 1200 400 2.0426 672 -1480.2 -169.5 -4.86 1604.9 +123.2 +42.39 20.43
| 1202 399 2.0476 670 -1487.3 -170.2 -4.87 1612.2 +123.6 +42.52 20.48
-------------------------------------------------------------------------------------
M = Peak vs. L.O.S, X = Set Zero, P = Max. Point Blank Range
Elevation above Angle of Site (0.0 deg.) = 0.0620 deg.

 

[Rob01]

Hornady in apparence did a very good job

They should have as they used the most accurate way to derive the BC in the doppler radar to get it. When people find it different it's usually something other than the actual bullet BC that is at work.

If using the Hornady bullets the 4Dof is very accurate.

 

[steve123]

You guys have me thinking hard about changing over to these from the 140 hybrids in my 8.5 twist 6.5 Saum. Man I could get these things going 3300 fps no sweat. At that speed I'd think .62 BC will be close and I use a .62 right now with those 140's.