-- A bonded bullet means simply that the core and jacket are bonded together making for high weight retention, deep penetration and bone-crushing capability. When considering the best of the bonded bullets, make sure the following factors are clearly explained on the box: retained weight, penetration and expansion.
A bullet like the Trophy Bonded Bear Claw features a copper jacket and lead core that are 100 percent bonded for reliable expansion and over 95% weight retention. From small deer to large elk and caribou, a quality bonded bullet will do the job - even if you happen to hit bone and need extra help from your projectile.
From Federal Premium Ammunition