This is a tuffy for me bc I own both, haa!. But for a paper puncher and midrange steel specifically, Id go the 6br route. Cheap to reload for, mild recoil, top end accuracy, long barrel life and idiot proof to load tune. You should routinely be shooting .30 moa or better at 100yds with a decent load all day long. Makes a nice varmint round too. The gun always brings a smile to my face. Might need some mag modifications to have it feed reliably however. Thusly mine's a single shot.
On the other hand my .284's sole purpose is to fill my desire for a high bc, good barrel life havin, LR fun gun niche. Its fire breathing overkill for shortrange paper and steel and thats why I built it for LR steel plates and other related mischief. Its also built on a stiller single action so I can seat the 162-180s with no feeding or COAL issues.