WebAug 19, 2024 · Greenhill formula. T=150 x D _____ R. T is the twist required (number of inches for one revolution), D is the bullet diameter (in inches) R is the bullet length to … WebNov 25, 2024 · The Greenhill formula is obsolete and will give a result with to fast a twist, except in LR, cast bullets (600+ yds). The reason is that the GH formula, doesn't solve for center of gravity. For the last 30 years, I've shot 1.16 - 1.19 long bullets, in my 14 twist Douglas barrel. 1450 fps range.
Twist rates for cast bullets as compared to jacketd bullets
WebJan 4, 2024 · In 2005, Don Miller refined Greenhill’s formula, and his work is widely used today in application to modern boattail rifle bullets. For we math and ballistics laymen who want to optimize the matchup between our loads and our rifles, today we have plug-and-play software programs, some available online at no cost. But they are not created equal. WebDec 3, 2010 · To apply the Greenhill Formula using the original 55 grain bullet yields the following, for one brand of full metal jacket (FMJ) military type bullet measuring .647″ in length. The bullet diameter is .224″, which … highschool of the dead vol. 3
.50 cal roundball with 1/48 rifling twist Graybeard Outdoors
Greenhill's formula is much more complicated in full form. The rule of thumb that Greenhill devised based upon his formula is actually what is seen in most writing, including Wikipedia. The rule of thumb is: The actual formula is: where WebNov 9, 2012 · With Bowman's alteration to the formula, the new Greenhill formula can be written as: Twist = 3.5 * sqrt(V) * D * D / L * sqrt(SG / 10.9) Let us work out the twist rate … WebSep 30, 2011 · The Greenhill Formula for minimum rifling twist for stabilization indicates that for a .38 bore with a 1 in 26 twist, the max bullet length would be .85" long. While the Greenhill formula would get one close, it is not a positive equation in all instances. Based on that, (Greenhill value of 170 instead of 150), the max bullet length in the 38/ ... highschool of the dead x male reader lemon