I sure jacked this thread, didn't I?
Allow me to present a sample of the first batch of cartridges made wholly possible through the impetus of this thread, and the patient guidance of our very own, highly regarded ballistics engineer, oldfart

It was my goal to replicate as closely as possible the often lauded 73 gn FMJ factory load by Sellier and Bellot out of the Czech Republic, which functions well in my pistol. The brass colored bullet is the factory S&B and the copper colored is a plated 71 gn Berry's. Matching the crimp and case dimensions took a bunch of tweaking, but I think I managed to get them as close as the limits that my cheap ebay/amazon calipers would allow. They stack in mags, feed, chamber, and eject as well as factory after manually cycling them a few times. I'm using regular CCI small pistol primers, but I want to give Federal a try as well.
Now all I need is some time to see how they shoot. I loaded up 2.1-2.3 gn charges per the Hodgdon manual and manually weighed each of them after they dropped out of the powder measure. I must say, the cheap Lee Auto Drum powder dropper is phenomenally accurate with the HP38. It has very fine adjustments that seem to handle this small range of charges to the point where I'm comfortable running this in a high throughput mode with occasional spot checking.
Materials cost for 100% new is 37 cents/rd (18 cents/rd if you don't include the virgin starline brass) at full retail prices total, exclusive of equipment costs. This is a big win already, as ammo availability locally is poor, and if I can find it, I would normally be set back around 50 cents plus a pop for these little guys.