I've been doing some looking around, and reading as much as I can find on the subject.
You drawing copper flats out to make jackets? IIRC what I read (one of Corbin's books, I think) the commercial makers annealed between draws on the jacket. The ones that were not using pure copper, were using a deep drawing alloy of copper and tin, as well, which made a difference.
I think the biggest hurdle to get past is the requirement for rigidity and plain old power, to move the material around, and to have the results come out pretty consistent. If you have room for a couple thousand pounds of thumping die press in your basement, it's easier.
IIRC there was a thread here a bit ago that had some pictures posted of the entry level equipment required to deep draw cartridge cases. I doubt that a machine as heavy would be required to draw cups for jackets, but to do a decent job of a 30 or 45 caliber jacket would take a fair bit of "whump".
Drawing rimfire cases. It worked well enough to start the Speer Bullet company. James Calhoon, too, on a smaller scale. Getting the cases cleaned out, seems to be a pretty major part of the work. After that, it's a matter of getting oneself set up with the correct mandrel and draw die diameter, with decent finishes on them.
Using diamond lapping pastes? How's that working out? Have not yet tried the stuff.
I'd like to set myself up to make .17 cal bullets. Was considering the option of drawing cases from copper flat, and pondering the potential results, vs. just buying a great bucket of J4 jackets to last me a lifetime or two, and getting on with a set of swaging dies to make the bullets from that start. But, it's the journey... Sometimes you gotta walk the path a while, to realize you should call a cab!
Corbins swaging stuff is pretty good, from all I've heard, except that you'll wait for years, and pay rather more than I figure I want to spend. But They have been pretty free with the information, and say outright that knowing how it's done is not the same thing as being able to do it. Not many substitutes available for hands-on experience!
Cheers
Trev