Impala bullets are a relatively new bullet design from South Africa and essentially solids.
This taken off their website http://impalabullets.co.za/impala-bullet-design:

"...Tissue displacement-not tissue destruction was the answer

His (the designer) approach was high frequency displacement rather than work done (J/s).

This resulted in a bullet which’s sharp cutting edge and nose design develops strong radial shock waves in the animal’s organs.

As no deformation is necessary the Impala bullets do not rely on a fine balance between impact velocity, bullet diameter, bullet mass and target resistance (skin, meat and bone). The bullets performance is machined into its profile using a CNC lathe other than conventional bullets that is dependant of the anatomical structure at point of entering the animal. The Impala Bullet is the only purposely manufactured shockwave inducing hunting bullet in the world.

Please comment

A further exert from the website.



One Concept – Three Bullets
Impala LWHV


The Light Weight High Velocity is the All-around Bullet.

Its incomparable flexibility permits its use at any distance, from springbuck and eland up to big dangerous game, including even buffalo and elephant.

Karoo

I'm confirmed lead bullet shooter. I use different lead alloys to achieve jacketed bullet velocities out of 30-06, 45-70, 405 Winchester and soon 8mm Mauser, as well as the full gammet of hand guns. The rifle bullets all have wide flat noses for use in tube magazines as well as transferring energy to the target.
Other then a few white tail deer I'm a relative novice.
The owner of LBT, Veral Smith, has pretty much killed the idea that the shoulder of Keith Semi Wad Cutter style bullets doesn't do the damage, rather it's the wide flat point.
It would appear that the Impala bullets are basically a take off on the Semi Wad Cutter.

jim