Boy that looks familiar! I've had to do that with every Ruger 45 Colt that I have, and I have a few! I makes a big difference when shooting cast bullets. I have a Redhawk 7.5" in 45 Colt coming in next week and I am sure I will need to do the same with that.
Ruger does get the 44's right. The only one I've had that was slightly tight was one of the recent SBH's that Talo had run with the 3.75" barrel.