Need help with 308 ballistics and Zeiss Rapid-Z 600

[tonyben]

I am installing a Zeiss 3x-9x X 50 with Rapid-Z 600 reticle on my 22" barreled M1A. I will be using 165grain Hornady BTSP running at 2600FPS. Zeiss has a holdover scale but It's too damn confusing to use. It's asking for BC's and such on their chart and I don't have the foggiest idea on how to find my BC.

What is my BC for my load so I can find the actual calibrated values of my reticle?

Thanks.

 

[pdog2225]

Tonyben, I ran your numbers through my Oehler Ballistic explorer program and it says your BC is .435 (zero to max).See if this will get you to or near what it predicts. pdog

 

[tonyben]

Thanks.

I plugged in the numbers and it looks like I picked the right reticle. It took me a while to figure out the form they have, but apparently, the calculator will give me the exact mag level to make the numbers coincide with the distance. It says if I set my mag level to 6.36 my holdover numbers will coincide with my distance.

I'm hunting in a couple of weeks so this will be very helpful.

 

[whiskey08]

this should help if you dont think the reticle isnt working for u



Manufacturer: Hornady Description: Boat Tail Spire Point
Caliber: 0.308 in Weight: 165.0 gr
Ballistic Coefficient: 0.435 G1

Muzzle Velocity: 2600.0 ft/s Distance to Chronograph: 5.0 ft

Sight Height: 1.90 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: 5.0 mph Wind Angle: 90.0 deg
Target Speed: 0.0 mph Target Angle: 0.0 deg

Temperature: 59.0 °F Pressure: 27.20 in Hg
Humidity: 0.0 % Altitude: 5000.0 ft

Vital Zone Radius: 5.0 in



Range Drop Drop Windage Windage Velocity
(yd) (in) (MOA) (in) (MOA) (ft/s)
0 -1.9 *** 0.0 *** 2602.6
50 -0.3 -0.5 0.1 0.1 2524.8
100 -0.0 -0.0 0.3 0.3 2448.3
150 -1.2 -0.8 0.7 0.5 2373.1
200 -3.9 -1.9 1.3 0.6 2299.3
250 -8.3 -3.2 2.1 0.8 2226.7
300 -14.4 -4.6 3.0 1.0 2155.4
350 -22.4 -6.1 4.2 1.1 2085.3
400 -32.4 -7.7 5.5 1.3 2016.6
450 -44.5 -9.4 7.1 1.5 1949.3
500 -58.9 -11.3 8.9 1.7 1883.4

 

[signut]

All of the above info is right on, but if possible you should take that load and do some range work and verify impacts at the suggested reticle powers. In theory, the charts etc. should be right on. In practice, range verified comeups ( especially if you can shoot at a similar altitude as your planned hunt ) are what I would trust. Just my .02 worth