Here is more information on the bullet illustrated in a short article by Rudi Keim published in the last ECRA bulletin (568-8). It was designated “Sonderausführung” (“Special design”) by DAG, who tested a few samples in 1987 and made a drawing of the sloted model.
It was designed by Charles Robert Emile Lamm, a French engineer who had a firm named Kentex R&D (KRD) in Buenos Aires which produced Browning HP accesories, speed loaders and ammunition of special type in 9 mm Parabellum and .38 Special + P.
This prototype weighs 67.1 gr (4.34 g) and, although is not finished, has a different profile and measurements than the fired one shown on the right (from DAG tests):
The final model commercialized in 1992 had a more rounded profile: