@valleyforge I agree, a 10/22 in 5.7 sounds totally feasible, considering the plethora of .22 WMR rifles from Ruger's competitors. The bolt thrust of 5.7 is a little higher on the account of the larger case head (if fluted), but P90 is a pure blowback and works great. If not 10/22, Ruger could make a version of PCC that takes 57 mags.
I called it