The Barnes TTSX bullet has received a modern polymer tip and a larger cavity to ensure better reliable expansion. Upon impact the four petals open and create massive hydraulic shock and penetrate deeply. These features increase the ballistic coefficient and ensure uniform expansion. They are an all copper boat tail bullet which makes them quite different to traditional style bullets. The team at Barnes Bullets have every right to be proud of this bullet. Have no fear in shooting these TTSX bullets at various velocities as they will not pull up short in an attempt to reach vital organs. Even when using magnum type rifles, penetration is not compromised and that bullet will go through and create a good exit wound with side on impacts. If you do your job these Bad Boys won't let you down.