It's a good cartridge. My experience is a mirror of Keith's....... 50gr. accuracy/field loads at 3650-3825 depending on powder and bullet. I'm using the 3825 load. Most accurate 55's are in the .3's at about 3650, and the 40's are accurate (ragged hole) anywhere from high 3900's to just shy of 4200. You can compare that to whatever you're used to with the .223. But it's a definite step up. The barrel is 25" Rem. varmint contour Schneider, 14" twist, brass is the very tough and no longer available IMI. The barrel is braked and a pleasure to shoot. When doing one of these be sure the riflebuilder is well versed in AI cartridges and has a good reamer. Best to just whack the old threads off for a complete new throat and neck. I strongly recommend 0 (zero) freebore, and .250" neck if that'll give you .002-.003" clearance on all your brass. Also don't just automatically trim brass to 'trim to" length, keep it as long as possible. And they talk about .004" crush on a new case......that would be fine if all cases were exactly the same length, but they're not and only .004" will leave you with no crush on some cases. My gun is set with .015" crush and it's not too much, there's very little bolt handle pressure when chambering a round. Fireforming 1000K or so rounds, except for load workup all of them were shot at either a groundsquirrel or prairie dog, along with some 'chucks. They were all going faster than a standard .223 round. Only real downside is that some guns have to be tweaked a bit to feed smoothly. Mine was like that. Remedy was to slightly modify the solid follower, polish the feed ramp, and give the outside face of the bolt front a good polish for the casehead to slide smoothly. Also the outside edge of the chamber - the very back edge - is beveled slightly, looks like about a 45 degree.