Boomer said:That is simply nonsense. I have owned rifle barrels with very fast twists and I witnessed no loss of accuracy with light bullets. In a .30 caliber rifle a 1:10 twist will stabilize a very wide range of bullet weights - one of the most accurate bullets I've shot in a 1:10 barrel was Sierra's 125 gr flat base spitzer.
The only effect fast twists (1:7) have on light bullets is the explosive impacts from varmint bullets like Sierra's Blitz or Hornady's SX. In my experience accuracy is not effected.
With due all respect what kind of accuracy we talking about?
Have you ever hear about Greenhill formula?
One of the first persons to try to develop a formula for calculating the correct rate of twist for firearms, was George Greenhill, a mathematics lecturer at Emanuel College in Cambridge, England. His formula is based on the rule that the twist required in calibers equals 150 divided by the length of the bullet in calibers. This can be simplified to:
Twist = 150 X D2/L
Where:
D = bullet diameter in inches
L= bullet length in inches
150 = a constant
This formula had limitations, but worked well up to and in the vicinity of about 1,800 f.p.s. For higher velocities most ballistic experts suggest substituting 180 for 150 in the formula. The twist formulas used in the Load From a Disk program, featured at this web site, uses a modified Greenhill formula in which the "150" constant is replaced by a series of equations that allow corrections for muzzle velocity from 1,100 to 4,000 fps.
Also here is a simple link to Steve site which can help with bullet lenghts/twist question.
http://stevespages.com/page8e.htm