I've shot Starline brass for many years in several calibers,44 Magnum,45 Colt,and 458 SOCOM. I have never had any case failures like you have posted,and it is probably just some bad brass that is in that batch.
I would contact Starline,and they will probably want you to send back the entire box of brass for them to inspect.
Texas State Rifle Association
North American Hunting Club