All I can add is when I was having my 35 whelen ackley built, which was subsequently re-chambered to a 350 Rigby, I e-mailed Woodleigh to see if the 1-14" would stabalize their 310 gr bullet. There response was, we can't say, but they did say that the 1-16" is too slow, and the 1-12" is just right.

I never tested the 310 woodleighs so I dunno if 1-14 was sufficient or not.

If I had a 1-16" twist whelen, I'd load the 225 tsx and never look back.