Basically, they are a Interlock but they are also have a boat tail instead of a flat base. They have a high B.C. like the A-Max but are a hunting bullet instead of a target bullet. A great deer bullet, they have a relatively thin jacket and have a violent expansion with a impresive wound channel. A great long range bullet. At close range I have had them shed the jacket even though they are a Interlock. I had one shed a jacket two years ago on a whitetail at about 80 yards but it broke the shoulder and lodged on the oposite side just under the skin in the neck, dropped the deer in its tracks. The jacket was a perfect mushroom but I never found the core. I was shooting the 154gr out of my 280 at velocities that were to much for that bullet at that range. For deer its a great bullet, for a elk I would choose different.