So, I have a P50 and a Ruger 57, both in 5.7x28mm. Ammo is expensive. But other than the price difference I'm seeing no good reason to invest in 22 WMR and in particular a PMR 30. I figure that even if not optimum the Ruger is a more effective carry weapon than the PMR 30 and for home defense the P50 (if I ever get it to fire reliably) is likely more effective than anything in 22 WMR. Ammo price is the only advantage that the 22 WMR weapons have near as I can tell.