GOB. That "redish" brass sounds like stuff that has been sitting out in the sun and has oxidized. Should be a deep reddish brown in color. Stuff loads and shoots just fine. The only thing I know of that will remove the oxidation is Worcestershire sauce.
Soak some 0000 steel wool with the W/S and twirl the brass with the four O betwen your soon to be sore fingers and you'll have sone pretty in pink brass. I did that with some 30-06 brass and it came out pink.
Shot just fine though. It's that green stuff, verdigis that can end up eating holes in brass.
Mr. 16 Gauge. I hear you on some brittle brass. I once bought two boxed (100 rounds) of Federal brand target ammo to compare against my home cast target wadcutter loads. Almost 50 percent split lengthwise and accuracy sucked big time.
That's with brand new factory ammo.
That stuff was expensive.
Paul B.