Imr 4350 mv variation.

[Mtstalker]

I got a new balistics app (shooter) and upon entering load data i see it asks for a muzzle velocity variation number noted as fps/°. Does anybody know the number for fps to degree for imr 4350? I searched and the numers people post range from .4fps/° to 1.9fps/°. Thanks.

 

[Langey]

I got a new balistics app (shooter) and upon entering load data i see it asks for a muzzle velocity variation number noted as fps/°. Does anybody know the number for fps to degree for imr 4350? I searched and the numers people post range from .4fps/° to 1.9fps/°. Thanks.

I tried three different cartridges in Quickload, 243 Win, 30 - 06 and 22 - 250. The powder charges (IMR 4350) were held constant and the temperatures were changed by 1 degree F. The temperatures entered into the program were from 75 degrees F to 50 degrees F. The average velocity loss per 1 degree drop in temperature is as follows:

22 - 250 = 2.20
243 = 1.32
30 - 06 = 1.48

 

[Mtstalker]

Thank you. Im loading for a 300 win mag. Do you think 1.3 would be a appropriate number?

 

[Langey]

Thank you. Im loading for a 300 win mag. Do you think 1.3 would be a appropriate number?

I just ran the 300 win mag. through Quickload and it averaged 1.24.

 

[Mtstalker]

awesome! thanks for the information.

 

[Deton8tor]

I just PM'd you a chart with the info you need.