Re: Any LR reload info for Wby 300 mag?
thanks Jay. Couple questions, I understand that new WBY's have a 1 to 10" twist and mine which is around 15 years old has a 1 to 12" twist with 26" barrel.
Tell me what your twist rate is? I am guessing it's the faster rate as you shoot the 190 with great accuracy.
I found the following information which I will take the liberty of pasting as it may help others....
The correct rifling twist rate for a particular bullet can also be calculated by using a formula originated by Sir Alfred Greenhill during the late 1800s. Simply divide a constant of 150 by the length of the bullet (in calibers) and then multiply by the diameter of the bullet (in inches).
For example, using the Roberts again, the Speer 120grain spitzer has a diameter of .257 inch and a length of 1.125 inches. Dividing that bullet’s length by its diameter gives us 4.38. Divide 150 by 4.38 and multiply the result by .257 and you arrive at a rifling twist rate of 8.80 inches. Rounding off to the next highest number gives us a twist rate of 1:9 inches which, as I said before, is correct for the .257 Roberts when it is loaded with a 120grain spitzer.
So using the above calculations I am going to need a bullet under 170 grains. By my calculations 180 Etip requires a 1 to 10" twist. A 180 Accubond requires a 1 to 10" twist also. I happen to have a 165 grain Game King (just using as an example) that calculates out to a 1 to 12" twist.
Possibly this is why I am seeing a difference from the kind posters in bullet weights.
Any thoughts on my post?
