With a 44 magnum you could do well at 100 yards, off a bench rest. My 45 Colt Bisley can shoot 2" to 4" groups at that distance, rested on bags and with the right loads. I use a 2X Leupold handgun scope that I had laying around. I think that with a 4X scope, that gun could shoot even better.
My gun/scope combo is heavy, I am old, and I would not expect much if I were shooting it without some kind of support.