Once manufactures figure out the trinity they'll have it licked Twist, mag constraint and throat I'm not holding my breath
MRC utilizes a 3.125" mag box in short actions. In a 260 and 308, I've yet to encounter a bullet that will not jam into the lands and still load into the mag box. They will run twist rates as requested. There is a group buy in progress in the Hunting Rifle section with details. The 1:10 is standard for the 308 and will run anything a 308 can push, and 1:9 for 260, but the group buy is for 1:8.
