I used to use core lokts, but two seasons ago I shot a whitetail buck in the shoulder at 50 yards with a 7 mag using core lokt ammo (I forget the grain) and the bullet exploded. There was very little penatration and the deer ran a couple of hundred yards before falling. The bullet had fragmented so much that when I was cleaning the deer a friend came walking up and thought I had gut shot the deer because the innards had been ruptured and that nasty smell was in the air. I had never had any complaints about core lokts up until that point. I decided to give Remington Premium Sciroccos a try and am very happy with their performance. I do not plan to use core lokts again, because if the deer I shot had been at 300 yards and the bullet exploded I doubt I would have found him.