PDA

View Full Version : Need Balistic Coefficent of 311365



CENTEX BILL
03-29-2013, 09:51 AM
I am begining to play with a Rebarreled Rolling Block with heavy octagon barrel in 30-30 with 1 in 10 twist. I hope to shoot this rifle in Cowboy gong matches out to 400 yards.

I have the NOE mold 311365 which I plan to use. Does anyone have a good guesstimate on what the ballistic coefficent would be on this boolit. Velocity ranges for the load will be 1500-1700 FPS. A friend has a ballistic computer program that we will plug the data in.

Appreciation in advance for you help.

Thanks,

Centex Bill

Doc Highwall
03-29-2013, 10:15 AM
Check the old posts under Group Buy Archives or Group Buy Results you might find something there.

Tom Myers
03-29-2013, 11:13 AM
I am begining to play with a Rebarreled Rolling Block with heavy octagon barrel in 30-30 with 1 in 10 twist. I hope to shoot this rifle in Cowboy gong matches out to 400 yards.

I have the NOE mold 311365 which I plan to use. Does anyone have a good guesstimate on what the ballistic coefficent would be on this boolit. Velocity ranges for the load will be 1500-1700 FPS. A friend has a ballistic computer program that we will plug the data in.

Appreciation in advance for you help.

Thanks,

Centex Bill

Bill,

I scaled out the NOE mold in my Precision Bullet Design software (http://www.tmtpages.com/draw/draw.htm) and it estimated a Ballistic Coefficient of 0.3983.

Please remember that, although the dimensions entered into my software are reasonably close, they were estimated from a scale drawing and also be aware that software can only estimate a ballistic coefficient.

Also be aware that bullet weight affects BC values proportionally, so the estimated values would change according to the bullet alloy used in the castings.

Your mileage may vary but this should get you into the ballpark

Hope this helps.

http://www.tmtpages.com/LinkSkyImages/forum_images/NOE%20Molds/NOE%20311365.png

Doc Highwall
03-29-2013, 12:00 PM
Thank You for posting that Tom!