I'm no expert on the .220 Swift but 1:14" twist rate is pretty universally standard. Unless it's a custom tube on that Ruger it's not going to be 1:8"...
Some factory built .220 Swift's may have a 1:12" twist, but I don't think you'll find any factory tubes twisted faster than that.
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.” ― Patrick Rothfuss, The Wise Man's Fear
