Starline is a good quality brass.
About a dozen years back, I met with Mr. Hayden, a dedicated shooter and staunch freedom believer.
He had a partner when I met him at a trade show, and they were both very adamant about making an affordable product, at least as good, or better than the other major US and even foreign competitors.
Their biggest issue, even then, was finding a producer willing to supply them with the mix of elements they requested. Even though they use a lot of the brass composite, it's not enough to initiate batches of the metal which producers have to change over all sorts of things for, and still be profitable.
It boils down to cost of the metal, so they piggy back onto other orders from other brass manufacturers.
They told me at the time, "Our machines are always kept in very good condition and worn components are quickly replaced, to ensure fine quality."
Those fellows are gone now, but I believe the business is still in the family, and the management is still keeping up their standards.
Starline brass is the Ruger of cartridge cases for reloading. There are better products out there, but much more expensive, for not much gain.