WebJun 30, 2011 · Registered. Joined Jan 3, 2003. 1,898 Posts. #5 · Jun 2, 2011. I once pulled and measured some 22WMR 30, 40 and 50 grain projectiles then used the greenhill formula to calculate "ideal" twist rates. I do not have the exact figures anymore but my results were basically. 30 grain = 1:18. 40 grain = 1:16. 50 grain = 1:14. WebThe 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: [3] where …
Firearm Calc
WebJan 5, 2024 · Iffland HV 223 barrel = 9” twist. All these guns/barrels will stabilize all the bullets shown, suggesting that the Greenhill formula is very conservative, that slower twists than Greenhill will stabilize bullets. Impressions. With a pointy bullet, the point sorta doesn’t count as length, for Greenhill. WebMar 30, 2024 · The Greenhill formula indicates that a proper twist rate for this bullet would be 32 inches. Interesting, eh, that so many handgun bullets should end up with so similar calculated twist rates? The twist on … bitwar data recovery 評価
Smith & Wesson Forum - Barrel Twist Rates
WebJun 2, 2015 · The Greenhill Rifling Formula is used to calculate the optimal barrel twist rate for stabilizing a bullet's flight given the bullet's diameter(D), length(L), specific gravity … WebOct 8, 2010 · Bottom Line Up Front - The Greenhill Twist Rate formula is not valid for round balls, either mathematically or physically, and the real-world reasons why rifling is beneficial for round balls are not predicted or modeled at all in Greenhill's formula. I don't shoot muzzleloaders, but I'd always wondered why some rifles that shot round balls had … WebJan 4, 2024 · Berger’s Twist Rate Calculator is perhaps the most comprehensive, yet at the same time the least-complex for the layman. There are only eight input fields: BC, bullet caliber, bullet weight, bullet length, muzzle velocity, barrel twist, temperature and altitude. bitwarden active directory integration