That's the usual complaint about all of the hard cast SWC/wide flat point bullets. They penetrate lots, but don't kill very quickly.
I've never seen any need for the 300 gr. class stuff. The older 250 gr. stuff has a long record of penetrating plenty in any live target. Even the softer 240 gr. lead factory loads have long had this rep of plenty of penetration.
It is possible to get too little penetration with some of the lighter, faster hollow point juacket bullets I understand. E