Hello!
That bullet is a complete new designed bullet. Maybe the wounding effect is compareable to grooves bullets but there are some interesting new details.
The rings of that bullet called (Führbänder) are different in every caliber and reduce pressure and barrelerosion dramaticly (patented). The first ring is always sharp for cutting hair from the hidden animal. The copper is not as hard as brnes x for example. They are made very accuratly and shoot flat, fast and accurate. Because of the "Führbänder" you can put more powder behind this bullet without getting more pressure!
I ordered some bullets and last week i shot a fox at 130 meters. First i was afraid that this hollow copperhuntingbullet does not expand on small animals like a fox but it did! The exithole was just about 8cm. The 164grain KJG makes out of my 8x68S 3200 fps and that is not a maximum load! The bullets have been tested in finnland on Whitetail and on boars in Germany and they worked fine and penetrated without tumbling perfectly.
If i were you i would just ask Lutz Möller , when you have some more questions he speaks english and is a real hunter...