@Bob Nelson 35Whelen
Thanks for catching that, Bob. Yeah, I did screw up the twist rates in my post.
My M600s and M660 have the 1:16 twist, not 1:14. The Ruger 77s in .350RM had 1:12 twists, at least those 22”-barreled rifles in the second run that Ruger did about 2006.
So yes, with the longer/heavier .358 bullets, the 1:16 barrels will have issues. That’s why I said the 275grn bullets might be the cut-off weight for stabilization (and thus accuracy) in .358 1:16 barrels (1:16 being what I had meant to say in my earlier post).
I’m hoping Woodleigh can get back up to speed on his .358-line of bullets. I haven’t been able to find his 275-grainers anywhere. MidywayUSA used to stock them.