hunter,
The gun modification is easy, just mod the rim cut and extractor (don't use an ejector barrel for this) to accommodate the larger OD of a 410 hull. You are now done with the gun, assuming it is an H&R 444M Handi Rifle.
Now the hard part. Figure out how to modify a brass/plastic 410 hull to one, accept a 44 cal bullet and two chamber into a 444M chamber. There is a bunch of trimming, neck sizing, hull resizing etc. required plus a bit of the unknown in load development to make this work. I had to make my own dies and a reamer to modify the hulls to work.
You might be able to make this work using all brass 410 hulls, but I am not sure as I never tried. All brass shotgun hulls are not legal for deer hunting in my state.
Once Matt gets the lost posts restored there are a couple of threads with a bit more detail on this. Right now I am going off my memory and it ain't so good. Three years ago I made what I thought was a lifetime supply of slugs and I haven't made any since. I made need to re-read my own posts before I can make anymore hulls.
To answer your question, yes it can be done again, but just not by me. HBB (Honing Big Bore, IIRC) can make you a fully rifled 410, but it is on a Encore platform. They can also provide you with the ammo.
Good luck,
BB