I don't know about acuracy with heel based, but I love the 165 grain hollow base. I use a rapine mould and even though it's one at a time, I cast while I'm panlubing the 45's and it goes pretty quik.
I haven't tried acuracy from a rest, but with 17 grains of Swiss 3f black powder it shoots better than I can offhand with the curent sights. Of all the recovered bullets(I have a hard time getting free pure lead) I haven't seen one that didn't open and fully engrave on the rifling.
That said, if your realy serious about acuracy, have the barrel bored out and linned with a .357-358 dia. linner with the correct rifling. Then you can use regular 38 bullets and have the proper rifling for a bullet instead of shooting a bullet with round ball rifling. I've thought about it and if I can ever find barrel linners that don't cost an arm and a leg I'm going to do that to mine.
I don't care for the R&D conversions on the colts, though for the remington I prefere it to the Kirst. The Kirst works like the original cartrige conversions, with the port in the frame and you don't have to remove the barrel and cylinder just to load.
Good luck and make some smoke!