Are you asking "is the cylinder frame the same"?
To the best of my knowledge, the answer would be no. The .44 Specials are made on the '55 Blackhawk sized frame.
Ruger Vaqueros use the '56 .44 magnum Blackhawk sized cylinder frames.
Now, if you mean a New Vaquero sheriff model then the answer would be yes.
I hope I understood your question........
flatgate