I am a commercial caster. A few years ago I had a local plating company plate a few thousand bullets. The objective was to see how thick the plating should be to eliminate leading, ie to do the same as jacketed bullets. I found that two thousandths was enough. Strings of 100 fired from a 9mm and a 357 Mag left the bores clean with no leading at all. I never took it further because having an outside contractor do it was too expensive, and the equipment was too big for my small workshop.
There was a company in business a few years back that sold a home brew kit for the home caster to plate their own bullets in copper. It had a plug in electric unit and all the chemicals necessary to get the job done including contracting out a series of undersized molds (not sure who made them for the company) that allowed you to plate yourself back into proper bullet diameters after the whole process was done and over with. It took off for a while but quickly lost interest and I believe the company went bust (I may be wrong on this?) The business end of the unit was a rack that had a series of spring loaded clamps or pins that were lifted so a cast bullet could be placed between the pins and held captive. The pins made the electrical connection and the rack was placed into the chemicals which were in a standard 5 gallon plastic bucket. Real simple equipment and I don't believe that the set up cost all that much either. The other neat thing was it was the only way to get a jacketed Keith type of bullet in 300 grains for your 45. All sorts of nifty combinations were then available with that unit. Smithy.