I do the same thing with .357 to shoot my M19's. 800 fps with a magnum case. How's that for wimpy, limp wrist shooting? I shot a friends 44 mag Anaconda with factory ammo. The muzzle flip was exciting. I had some 44 spl ammo and it was pleasant.
If I'm not careful I'm going to talk myself into a 44 spl revolver with all heartache of finding bullets and dies to load it. I think I would rather have a 44 mag and load it down. Dirty Harry would not approve.