I seem to fit in with a lot of the other casters - I'm 68 and started casting around 1968 or 69. I had a couple of older mentors who were casting for old rifles that needed custom made ammunition to get them to perform well - 25-20 Single shot, 32-40, 38-55 and 45-70. I was working in a gas station while going to school and got free lead wheel weights and had friends that were in the trades and would scarf up lead from plumbers and roofers. Working with molten lead seemed perfectly normal since I used to help my grand dad pour lead joints in cast iron pipe (much to my mom's consternation).
I shot NRA Bullseye for a long time and cast my .38 and .45 match bullets in Hensley & Gibbs moulds. Then came PPC, IPSC, bowling pins and Cowboy Action Shooting. I cast for all of these except when I had access to cowboy bullets from an area bullet maker. His bullets were excellent and very reasonably priced when bought in quantity and he delivered to the range. Oh, I also bought some hollow base .38 wadcutters for the 50 yard stage of bullseye for use in my Model 52.
My serious competition days are over but still pump out a lot of 9mm, 38 and 45 cast bullets for practice which made me appreciate the less expensive aluminum 6 cavity moulds that Lee makes. The majority of my moulds are Ideal/Lyman with some Ohaus/RCBS. These are in sizes like 30 Luger, 30 Mauser, 32-20, 38 S&W, 38-55, 44-40 and 45-70. Most of my casting for rifle is split between 30 calibers like 30-30, 30-06 and 30-40 and the 45-70. There is some .303 and 8mm too as well as round balls and .58 Minies but in small quantities. I've never had much success with cast bullets smaller than 30 caliber so I've stayed away from .22, .25 and 7mm calibers.
I'm not seeing any of the younger folks in my area get involved in bullet casting and lead is getting harder to find for free or at low prices. Luckily I've got enough lead for the foreseeable future plus a dwindling supply of "type metal" that I was given when the local paper changed their printing process years ago.