Shooting lead/ casting bullets is its own hobby all together. Also shooting lead is almost 100 times cheaper then copper or jacketed. I pay 25 cents a pound for lead and cast around 30-70 bullets for that cost. You get into paper patching, gaschecks, different lubes, different bullet fit.( bore size to upwards of 0.005" over bore) play with difference hardnesses of the lead for different velocitys.
When i get back to work ill post a pic of lead expansion from shooting at cow bone. Its a 30 cal 180gr that opened up to 1.5" dia, flatten to about 0.250" tall and still weighs 174gr. Any softer or harder lead/ any more velocity would have caused that not to happen.
Also lots of old guns run real low pressure, so also low velocity, jacketed wouldnt work at all. And you get more expansion with lead.
And its hard to find jacketed bullets in odd sizes like .446" dia. Cast you can make near any size.