Greenhill formula for rifling twist
WebCalculates the Miller stability factor. This formula was derived by Don Miller and published in Precision Shooting. This formula is much better than the antiquated Greenhill's … WebFeb 12, 2015 · The Greenhill formula was created in the late 1800's to calculate (estimate) rifling twist to stabilize a bullet-length. I have found it to be very vague and not useful. Have any of the current gun manufactures (in the past century) come out with any chart for twist rate vs bullet length...
Greenhill formula for rifling twist
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WebThe Miller Twist Rule is used to calculate the optimal barrel twist rate for stabilizing a bullet's flight given the bullet's diameter(D), length(L) and mass (m) . WebNov 5, 2024 · In 1879, British mathematician Alfred Greenhill developed a simple formula for determining rifling twist rates for stabilizing bullets. Though overtaken somewhat by updated math and software programs, …
WebMar 7, 2024 · Barrel twist rates are determined by using either the Greenhill or Miller formulas.. Generally the lighter the bullet for a given barrel the slower the twist. Velocity is not part of the equation.. Best examples l can think of to illustrate this principle is 223Rem. When first introduced most barrels had a 1 in 12 twist for a 55gr bullet. WebThis formula is much better than the antiquated Greenhill's formula. Stability value should be in the range of 1.3 to 2.0 to ensure bullet stability. Don Miller and Dave Brennan (editor of Precision Shooting) have also been kind enough to let me host his stability paper on my exterior ballistics bibliograpy page.
WebSep 4, 2011 · When it comes to shooting conicals, you are talking different considerations, shallower grooves, and the Greenhill formula dictates the use of even faster Rates of Twist in the rifling as the length of the bullet increases, to stabilize the bullets in air. If you like FAST ROTs, the current US military battle rifle now comes rifled with a 1:7" ROT. 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 …
WebThe Greenhill Formula does not, however, take into account bullet shape or muzzle velocity. Both parameters come into play especially when you approach the limit of what a …
WebThe eponymous Greenhill Formula, still used today, is: where: C = 150 (use 180 for muzzle velocities higher than 2,800 f/s) D = bullet's diameter in inches L = bullet's length in inches SG = bullet's specific gravity (10.9 for lead-core bullets, which cancels out the second half of … orbeez guns to buyWebMay 8, 2004 · According to Greenhill's formula, then, the proper rate of twist for the Sierra .30-caliber, 200-gr MatchKing is 1:10". That said, and with all due respect to Greenhill, some long-range [smokeless powder] shooters are experimenting with slower rates of twist. 1) .900" long .62-cal (.625") bullet needs 1:65" twist.. ipni - the international plant names indexWebOct 27, 2024 · Greenhill's Formula is expressed as follows: T = CD 2 x √SG Rifling twist rates for small arms are expressed in either inches or millimeters per turn. In general, … orbeez gun with drum magWebAug 15, 2024 · Don Miller developed this formula as a more accurate way to find an ideal rifle twist rate. Whereas Greenhill was more of a generic formula, Miller’s uses more characteristics of a rifle bullet to arrive a a … orbeez gun what is itWebMay 16, 2014 · This is a quote from Ballistic ENGLE research Greenhill Formula for Rifling Twists The Time-honored Greenhill formula was originally used for determining twist rates in the new rifled artillery in the 19th Century.. It is important to note that it is projectile *length*, not *weight* which is the determining factor when considering the best ... ipnm icdhttp://kwk.us/twist.html orbeez highest ratedWebSep 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/ ... orbeez in a bathtub