This is kind of round-about logic, but I was looking at twist rates in the Single Six convertible vs. their one caliber only Single Ten .22 LR and noted they are both 1:14. All other single caliber .22 LR revolvers and pistols - LCR, SP101, GP100, SR22 and Mk IV are 1:16 twist. It's not proof positive but it leads one to believe that the LCR and other 1:16 twist handguns are bored properly for the smaller .22 LR bullet.
I asked Ruger about their bore diameters in February and they replied: ""The bore diameter for the new model single six family is .219 MIN MIN. DP. OF GROOVE .002 The groove diameter is .2240/.2255", i.e. all Single whatever SA revolvers are nominally .224 bore diameter for the .22 magnum.
My full post in Handguns in February: https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/ubb/showflat/Number/11806272/Searchpage/1/Main/811300/Words/%2Bruger/Search/true/ruger-single-action-22-groove-diameter-the-final-word#Post11806272
I emailed Ruger about the groove diameter of their .22 SA revolvers. I had read often enough that the Single Six Convertible was bored for the .22 WMR so nominally was .224", whereas .22 LR bullets are .222-.223" in diameter. But the hope was that the Single Ten made specifically for the .22 LR was bored properly. Apparently not so.
From the horse's mouth:
"The bore diameter for the new model single six family is .219 MIN MIN. DP. OF GROOVE .002 The groove diameter is .2240/.2255"
I underlined "family" since I am going to assume that means the Single Ten, which I had specifically asked about. I was looking at twist rates and noted that the Single Six, Ten and Nine all had 1:14 twists but every other .22 Ruger makes had a 1:16 twist, that's another indication that they use the same barrels on all of the Single Six/Ten/Nine revolvers.
