Todd,
I agree with your thinking.
Try the 120gr x.
Make sure you do not try to load them close to the lands. About .05 back should work for you.
Make sure your barrel is as clean as possible before trying the x bullets.
Start your loads well below max loads in your reload book, x bullets will sometimes not take a full max load of powder that other bullets may take.

If you can't get the 120's to shoot then try the 140gr Triple Shocks. People have been having excellent results with them. I have had my best luck with IMR4831 with the Barnes bullets in several calibers.
Good luck!