I have a fast twist (1-7) 22-250 AI. I shoot the 75 grain A Max at 3,010 fps. I have never shot anything lighter than a 63 in the rifle. It is my crow gun. Best shot so far was 354 yards on a crow. If you want a custom 224 gun, the 22-250 AI with a 1-8 twist is the way to go in my opinion. The 1-8 is more versitile than the 1-7 twist I have and is what I would build were I going to do er again. While the BR and PPC are straining to get to 3,000 with a heavy bullet the AI is lounging at 3,000 with an 80 grainer. Oh and 75 or 80 grains in a 224 is not the same as 75 or 80 grains in a 243, a big difference in the SD and BC.
I have a CM Remington 700 BDL action that has been blue printed, squared, lapped, threads cut .010 over, bolt handle replaced with a Brownells long model and then bolt and action were satin hard chromed. The stainless recoil lug is oversised for the threads, pinned and is oversized in thickness. It was shaped to a .000 tolerance on both sides. The barrel is a 26 inch Lothar Walther heavy sporter, match, SS,computer lapped, 1-7 twist, with 8 flutes. Stock is HS Precision with Harris bipod. Trigger is single set 4 oz Kipplinger. Scope is an 8x34x56 Hakko MPZ, ranging side focus, lit, mill dot reticle, military and police model.
Truth is though, my 260s all shoot as good as the 22-250. Worse, the 260s shoot better with the 85, 100 and 120 Sierras. Two of my 260 shoot the 120s over 3,200 fps, under .20 inches. Not much need for any varmit gun with them around. But then again, this ain't about need, is it....
Ed