I personally use the "shake and bake" method. I use an old kool whip container, add bullets and powder. Shake like hell. Dump thru a mesh screen, and onto a tray wrapped in non-stick foil. Then I bake in an old convection oven in my garage.

I tried the spray gun since I already had one for motorcycle and boat parts. It's too much work for what I get out of it.

Some guys tumble in a dedicated bowl for their brass tumbler. I don't do that either because shaking by hand works fine for me.

You're going to have to experiment and find out what works best for you. Weather/humidity is a huge variable for what works for some but not others.

I happen to live in S. Florida. In theory, some of what works for me shouldn't because of the humidity. But somehow it's working.