This algorithm and the constant 3.5 was suggested by Charlie Dell, in his book, "The Modern Schuetzen Rifle" and brought to my attention by "Tailhook" a member of the MSN BPCR discussion forum.
The constant "3.5" may be re-calculated to conform to known twist-length-velocity combinations that have been proven to produce bullet stability.

Define the Variables:
T = Twist rate in 1 turn per inches.
L = Bullet length in inches.
V = Muzzle Velocity
D = Diameter of the bore grooves in inches.
Constant = 3.5

Find the optimum twist rate from velocity, bore size and bullet length:
T= ( 3.5 * SqRt( V ) * D² ) ÷ L

Find the optimum bullet length from velocity, bore size and twist rate:
L = ( 3.5 * SqRt( V ) * D² ) ÷ T

Find the optimum muzzle velocity from bullet length, bore size and twist rate:
V = ( L * T ÷ D² ÷ 3.5 )²

Find a different constant to fit known optimim combinations.
Constant = L * T ÷ D² ÷ SqRt( V )

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Last revised: May 17, 2007.