I have two RimX rifles in 17 WSM, awesome rifles!! As you stated a little heavy for hunting, but perfect on tripod. I am now using ARCA rail on everything I can. What chassis frame are you using?I have 2 proof 22lr barrels, one 20 inch carbon that came on the gun and a spare steel. Carbon barrel shoots good enough that i never installed the steel barrel to test it. The 17wsm is a 20 inch preferred barrel, still haven't shot it yet. I can hopefully get you a report this week. The rim x action is awesome setup, a little heavy but well built. I actually have another 17wsm barrel on order from preferred to try and reduce the weight some to make it a hunting gun, hoping it will be here soon.
Thanks