Varminter,
I just noticed you are in E Tenn. You need to talk to JPH45 on this forum. he's in Mentone, Alabama (just south of you) , and knows A LOT more than I do about cast bullets in general, and more about this particular Handi Rifle in 44mag. He's spend a good bit of time working to get his shooting well. Apparently his bore slugged out at .432 like mine.
Drop him a PM, I'm sure you be pleased with the info he'll give you.
In fact, I wouldn't be surprized if he pops in on this thread soon.