I just came in to post about this drop chart I made tonight, when I saw your post. I figured I may as well post it in here. Since I tried that load posted everywhere with 26gr H4895 and the 39gr Sierra Blitzking the other day, and found it to be pretty close to useable in my rifle, I've been thinking about making up a chart like I've seen some have in their scope covers. I figured I may as well start with this
JBM Trajectory Calculation page, then can try shooting at several ranges to compare the actual results, and edit the chart as necessary. I just wanted a place to start.
This was the first time Ive used that page for the 204. What I found was pretty interesting.
I have my scope zeroed at 100 yards, because of that postal shoot that just wrapped up. I thought I'd be changing my zero to 200 one of these days, but now I don't know. I may leave it zeroed at 100.
The JBM chart I came up with for the 39gr Sierra Blitzking, at 3550fps with chrono 10 feet from muzzle, said with MY sight height of 2.62 (center of bore to center of scope), there SHOULD be .85" drop at 200 yards. Therefore I started my eyepiece chart at 250 yards. Since my scope has fingertip "click" adjustments, I wanted my chart to be in clicks instead of inches of drop. You can see that with 1/8moa clicks, it gets to be alot of clicks at longer ranges. I also wanted to do some testing with windage clicks, and the JBM chart gives me somewhere to start. If any of you see something terribly wrong with these numbers, please let me know. Might save me some ammo when I first go out to start testing to see how accurate this chart is.
If any of you want a chart like this let me know and I'd be glad to make one for you. I don't want to calculate yours, but send me a chart and I'll send it back to you in a file you can print and cut out. If any of you want to try this one, you can click on the chart shown here. It will pop up a download of the pdf file for you to print at 1/1 scale. This one is blown up. The numbers are as small as I can read at 1/1. That's why I left out ranges below 250. Would not have needed to go to 600, but maybe it'd be fun to try hitting some prairie dogs that far away. We'll see how accurate this chart is.
JBM page output:
Trajectory Output
Input Data
Muzzle Velocity: 3550.0 ft/sec
Chronograph Distance: 10.000 feet
Ballistic Coefficient: 0.210 0-1900fps
Ballistic Coefficient: 0.236 1900-2300fps
Ballistic Coefficient: 0.255 2300-2800fps
Ballistic Coefficient: 0.270 2800-3600fps
Ballistic Coefficient: 0.287 3600-10000fps
Drag Function: G1
Bullet Weight: 39 grains
Sight Height: 2.62 inches
Sight Offset: 0.00 inches
Wind Range Speed: 0 mph
Wind Vertical Speed: 0 mph
Wind Cross Speed: 10 mph
LOS Angle: 0 degrees
Cant Angle: 0 degrees
Target Speed: 0 mph
Target Angle: 90 degrees
Zero Range: 100 yards
Zero Height: 0 inches
Zero Offset: 0 inches
Temperature: 68.0 °F
Barometric Pressure: 29.92 in Hg
Relative Humidity: 78.0 %
Altitude: 1345 feet
Air Density: 96.343 % of Dry Sea Level
Mach: 1126.1 ft/sec
Calculated Table
Elevation: 3.930 moa
Azimuth: 0.000 moa
Range Velocity Energy Moment Elev Wind Lead Slope Time
(yards) (ft/sec) (ft-lbs) (lb-sec) (moa) (moa) (moa) (in/yd) (sec)
50 3366.2 981.2 0.58 -1.77 0.42 0.0 +0.027 0.043
100 3177.2 874.2 0.55 -0.00 0.85 0.0 +0.010 0.089
150 2996.0 777.2 0.52 +0.04 1.30 0.0 -0.008 0.138
200 2821.8 689.5 0.49 -0.40 1.77 0.0 -0.028 0.189
250 2645.9 606.2 0.46 -1.09 2.28 0.0 -0.052 0.244
300 2475.9 530.8 0.43 -1.94 2.83 0.0 -0.078 0.303
350 2313.0 463.3 0.40 -2.93 3.41 0.0 -0.108 0.366
400 2144.7 398.3 0.37 -4.07 4.05 0.0 -0.143 0.433
450 1982.2 340.2 0.34 -5.36 4.75 0.0 -0.184 0.506
500 1818.7 286.4 0.31 -6.81 5.51 0.0 -0.232 0.585
550 1656.1 237.5 0.29 -8.45 6.37 0.0 -0.290 0.671
600 1505.8 196.3 0.26 -10.33 7.32 0.0 -0.360 0.766