at one time they were two separate websites.
the boolits site was piggybacking on the gunloads site. [you could click a link between the two places from the other site]
eventually the boolits site outrun the gunloads site and they basically merged into one to keep things simple.
if you look at the blue and orange CASTBOOLITS LOGO at the top of the page you'll see at the bottom where it shows
castboolits.gunloads.com that's the domain name here.