I'm about to start building test loads for a Browning/ Miroko Low Wall in 44 Mag. It appears to me that the 24" barrel has a twist rate is 1 in 20". I checked the throat and found that the lead into the rifling is a tapered ramp and not a sharp step. Also there is no problem with excessive free bore. The bullet can be seated as though it were to be loaded for a revolver and still make lead ramp/land contact. The bore scope shows a barrel that is in very good condition (Near New) and free of fouling. Pushing an oiled tight fitting patch through the bore there are not loose or tight spots, so the barrel appears to be OK. 
  The objective in this project is to develop two types of loadings. One that will make an accurate cast bullet load of mid-range velocity for plinking and informal target shooting, and one for hunting anything from woodchucks to deer. 
   With all that being said, I'd like to hear from those who have had experience with shooting cast bullets in 44 Mag single shots, and what they suggest for loads to fit my projective directive. I have a feeling that the loads used successfully in handguns will not be compatible in a longer barreled sealed breach firearm when it comes to accuracy.

The use of a little less powder seem logical. I'll give it a try. Will need to locate a few cast bullet like you have mentioned and give them a try. All that I have on hand is a 240 SWC BB. I'm getting the impression that the BB bullet are not that great in a rifle for accuracy. 
   

Frank, I've got some 265 grain jacketed soft point Hornady bullets. Maybe I should give them a try. How about the same suggested powder charge as you suggested for the cast 265 grain bullet?

                     Thanks, Sendaro

Frank, I had some rounds loaded for my revolver with 240 grain Hornady JHP bullets over 23 grains of H110. They shoot very well in my S&W M29 Sil. 10 3/8", so I gave them a try. They did OK at 50 yards, but not at 100 yards. They were all over the place. Looks like there were a few things here that should be changed. Powder charge maybe too heavy for the rifle loads best accuracy, heavy crimp, and the bullet should be heavier.
   What I refer to as too heavy for rifle loads in the base of the jacket on the bullet. I have seen where bullets designed for a handgun were shot in rifles and they has the base of the bullet cupped by the higher pressure. This pushed the lead core forward and distorted the bullet. They shot like crap!
   Heading to a gun show in Saratoga this AM. Will be on the look out for a mold. 
   I have a box of 265 grain Hornady JSP that I will try with your suggested charge weights. Will take the rifle, dies and loading stuff to my shooting house and do some test firing early next week. That way I can load right at the bench rest and test fire. Sure makes it easier than building many different loads in the shop and taking it to the range.
    I've got a bunch of H110, so it would be nice to have that powder be the one that works. Also I like the way it goes through the powder measure. My Harrell's measure drops it right on the money every time. 
                  Thanks, Sendaro