Free: Contests & Raffles.
Eric M, you may already know this but the weight of the bullet doesn't necessarily dictate the twist, as much as its design/profile does. A flat base 60gr bullet can get away with using a slower twist while a same weight VLD type bullet will require a faster twist to stabilize it. A good example is Hornady's 53gr Vmax. It has a very sleek profile with a relatively short bearing surface and nearly always requires at least a 1-12tw barrel but the nearly the same weight 52gr Amax, with its less sleek profile, lower BC, and longer bearing surface typically shoots extremely well from a 1-14tw 22-250. Generally, the higher the BC the faster the barrel twist needs to be.
It is the relationship between the twist of the rifling and the length of the bullet regardless of weight or nose shape that determines stability. It's known as the Greenhill formula."In 1879, Greenhill developed a rule of thumb for calculating the optimal twist rate for lead-core bullets. This shortcut uses the bullet's length, needing no allowances for weight or nose shape.[6] Greenhill applied this theory to account for the steadiness of flight conferred upon an elongated projectile by rifling. The eponymous Greenhill Formula, still used today"Retained velocity over distance is do to bullet shape BC, not stability.
Quote from: Bill W on January 11, 2018, 01:52:41 PMmine stabiliezed 60 grain Hornady HPs with a 12 inch twist.Just curious what was the maximum distance you shot? @theskybuster mentioned 200 yards and I have heard that from one other person that they might be fine out to 200.
mine stabiliezed 60 grain Hornady HPs with a 12 inch twist.
Quote from: Eric M on January 12, 2018, 12:03:00 PMQuote from: Bill W on January 11, 2018, 01:52:41 PMmine stabiliezed 60 grain Hornady HPs with a 12 inch twist.Just curious what was the maximum distance you shot? @theskybuster mentioned 200 yards and I have heard that from one other person that they might be fine out to 200.I only tried that bullet during load development at 100 yards. My notes from 2011 list the group sizes as between .7 to 1.3” (outside to outside of the hole). From Sierra’s website:.22 Caliber (.224) High Velocity 60 gr. HP (100 bullets) .22 CALIBER (.224) HIGH VELOCITY 60 GR. HPFor rifles, this is a high-velocity bullet designed to give precision accuracy with the explosive expansion of Sierra's Varminter-style construction. This bullet is at its best when fired from the larger-capacity cartridges, such as the 22-250 or 220 Swift in rifles with barrels having 1x14" twist rates, stabilizing easily for excellent long-range accuracy and effective expansion. Normally, 1x12" or faster twist rates work best for medium-capacity cases, such as the 223 Remington. These bullets are excellent for long-range varmint hunting. For handguns, although this bullet is of Hollow Point construction, we cannot recommend it for hunting purposes. This bullet has been very successful on half-size NRA Silhouette targets.The #1375 was introduced in 1984.
Why they haven't put out a fast twist 22-250 is beyond me.
Quote from: jasnt on January 13, 2018, 05:22:09 PMWhy they haven't put out a fast twist 22-250 is beyond me.I'm bar from any type of rifle expert. Why change what works? I would think faster twist equals faster barrel wear?
Being and older shooter(Old Fa-t according to my wife), when the 22-250 was legitimized there were no heavies available and the 22-250 was a benchrest, varmint and predator round. I don't believe even commercial bullet makers could produce a long heavy high rotational bullet at the time, we had a hard enough time getting 243 bullets that worked on big game. The 22-250 filled it's knitch perfectly as it had been doing as a wildcat before for years. Back then if you needed more bullet weight you went up in caliber until you got what you needed. Imagine how screw thing would be if now 1-8 became the norm and the bullet manufactures started to promote 80gr bullets for the 22-250 and thousands of 22-250 shooters can't get the new wizbang bullets through the paper any way but sideways. Just ask any oldtime Savage 99 250 Savage shooter, the latest bullets from the manufactured 250 Sav and a majority of old 99's won't shoot them accurately.What they need to do is bring out a fast twist .224 with about the same capacity as the 22-250 just for heavies that won't fit in a 22-250.
What they need to do is bring out a fast twist .224 with about the same capacity as the 22-250 just for heavies that won't fit in a 22-250.