These Ruger .44's are great guns with cast provided you use the right diameter bullets! Most commercial cast bullets at .429"-.430" are dismal in the accurracy department once pressures and velocities edge towards the upper envelope. However, using a hard, gas checked bullet of .432" diameter, lubed with a quality lubricant, these guns shoot like gangusters!
As far as bullet selection with cast. Any of the WFN series bullets from Beartooth will feed and flawlessly function from these rotary Ruger magazines!
.432"-240g WFNPB
.432"-265g WFNGC
.432"-280g WFNPB
.432"-280g WFNGC
.432"-300g WFNGC
As mentioned above, if seeking top velocities, choose the GC bullets. With the selections above, you should be able to do just about anything you want with that .44 Ruger, within normal limitations of course!
Oh, and by using .44 Spcl brass, the LFN series bullets all function properly through the Rotary Ruger magazines as well, but then load development must begin afresh with the shorter case and reduced case capacity, but it does allow using the bullets with a higher Ballistic Coefficient in your Ruger Rifle as well.
Hope this helps.
God Bless,
Marshall