Just to make the game a little more confusing...
The quarter rib fix can be more extensive than assuring no contact with the receiver. Many -- not all -- of the ribs are not "true", that is dead straight. My smith checks them and assures that they are not creating a twisting torque during barrel flex. Also, some swear by cutting a slot in the rib, in place of just a whole, where the front screw fastens to the barrel. The theory is that this prevents the rib from bending with each shot.
Also, some say that the set screw needs to have something to ride against on the barrel. Some smiths just 'dimple the barrel itself to create a secure little divot for the screw head. My smith uses some kind of plastic steel that bonds to the barrel and then is dished out to hold the screw head.
Kind of makes you wish that Ruger did all that for you in a custom shop. But then the #1 would cost @ $2000.
1B
