Originally Posted by Zombie Steve
The thin drawn jacket on most open tip match (hollow point bullets) lends itself to fragmentation. While I think they work better on soft targets than fmj, they are designed for flight and flight alone. They just have to punch a hole in paper or make steel ring. The hollow cavity in the tip is to move the center of gravity back on the bullet and help stabilization in flight. If you want expansion, get a hunting bullet. Soft point, partition / A-frame, or something bonded like the accubond or deep curl.
This is true. The bullet yaws and fragments much like the M193 style bullets of the 5.56mm (which is actually true for any pointed bullet with somewhat fragile construction).
They are much more effective than FMJ bullets against unarmored targets.