Problem is that HV long rifles are as potent or more than WRFs are, so they fell out of favor many years ago. Too bad they didn't speed them up a little instead of introducing the .22 Mag.... oh well, just like in todays world.... they keep introducing new cartridges to sell more guns, eg.: the new .17s, .204 Ruger, etc. No real need for them but gun magazines hype them for the companys and someone will buy them.
BTW, I shoot WRFs in the .22 mag. cylinder of my Ruger Single Six... work just fine and then I can carry it with CCI magnum shot shells in 2 holes and 3 WRFs in the others (it's an old 3 screw so carry one empty).