The bearclaw has a solid copper base that extends for about 1/2 the length of the bullet and the front 1/2 or so is a bonded lead core.In the case of the failsafe the front 1/2 or so of the bullet is solid copper with the rear half being a lead core surrounded by a steel cup.As far as performance the failsafes tend to penetrate more with less expansion while the bearclaws expand well but do not penetrate as much.The failsafe will almost always leave an exit hole that will make for easier tracking while the bearclaw will usually make a larger diameter wound which may cause a slightly quicker death.You really can't go wrong with either bullet.