There were three early Ruger SAs... The what is now called Mid-Frame Flat Top, .44 Magnum Flat Top and finally the .44 Super Backhawk with the protected rear sight.
In the early 60s Ruger dropped the Flat Tops and made all calibers built on the Super Blackhawk size frame. The gripframe however was different between the .44 Magnum and other calibers. The .44 used the larger squared backed trigger guard Dragoon frame and the Blackhawks were the XR3-RED which was just a little different from the original flat tops which were the XR3 that was close to the Colt SAA.
The .41 Magnum came out in the Old Model three screw BH in 1965 and is the same frame size as the .357 and .44 Magnum. It just continued into the New Model.
So everything .41 by Ruger is on the Large-Frame...
Bob
Not quite. I got some correct data from the Kuhnhausen shop
manual on Ruger single actions. Ruger three screw BHs were
built on two different frame sizes. One key to understanding
this is that there were two cyl diameters used as well. Early
BHs were flat tops and were built on the smaller frame size
and a cyl dia of 1.670 in .357 mag and .44 mag. In 1959 the
Super BH came out with a larger frame Ruger called the
sight protected frame, as opposed to flat top, and a cyl dia
of 1.730. There were a few flat top .44s built up to around
1963. The sight protected frame became the standard style
and the .357s still used the smaller frame and cyl dia until
the end of three screw production in 1972. The .41 mag
came out in 1965 and was apparently built on the .44 size
frame. When the New models came out in 1973 the .44
size frame with the larger cyl dia became standard for all
calibers including the .357.