Mr. Walkalong is certainly correct about the .222 Rem. being a long time darling of benchrest shooters before advent of the 6PPC. (Which, by the way, was developed to conform to a newly introduced benchrest classification requiring .243”/6mm caliber or larger.) But something that perhaps only old-time benchrest competitors such as myself will remember is that for about a 5 year period (Late ‘60’s, early 70’s) the .222 was significiently replaced by the .223 in bench competitions. One main reason being the record-breaking successes of Jim Stekl and his cute wife Donnalee, with rifles in .223 chambering. In addition to being a champion level competitor, Stekl was employed by Remington Arms and worked with Mike Walker in the design and development of rifles and cartridges. According to Stekl, anything the .222 could do accuracywise, the .223 could do better, and he proved it repeatedly. During that period virtually all .22 Cal. Match grade bullets, as made by Remington, Sierra, Speer and Winchester, plus those of us who made our own, weighed 52 or 53 grains. (There was no particular reason for that weight except to make it sound more exclusive.) The bottom line here is that the .223 rifles Stekl and his wife won tournaments with had 1/15” twist barrels, and with good reason. Which is why you’ll be losing more than you’re gaining with a twist faster than 1/14” if building a .223 Rem. rifle intended only for shooting 40 gr. Bullets. 14 and 40 go together like peaches and cream.