X-Nico

3 unusual facts about Miller twist rule


Miller twist rule

For example he states that assuming a mach number of M = 2.5 (or roughly 2800 ft/sec assuming standard conditions at sea level where 1 Mach is roughly 1116 ft/sec) is a safe value to use in regards to velocity.

The rule of thumb that Greenhill devised based upon his formula is actually what is seen in most places, including Wikipedia.

So our rifling should be roughly 12" per turn. The twist, as listed on Wikipedia's .30-06 article is 10" inches per turn as an average of .30-06 caliber rifles; thus 12" inches per turn is fairly accurate.



see also