I somehow got two cylinders in 22 Mag.  One is fluted, the other is not.  Both work great.  I have wanted to send it in to Ruger to get fitted for 22 RF, but they will do the safety conversion whether I want it or not, and I don't want it.  Anybody have an extra 22 RF cylinder?  I would make an even swap for either of my cylinders....fluted or non fluted.  I am sure my freind ( retired gunsmith) could tune up the cylinder without Ruger's help. Hmmmm.  I should probably run an ad in the classifieds.