The bullet you have is an older design. The jacket is made of mild steel. [does not hurt your barrel] Norma made these available in many diameters. I still have some in 6.5mm, 270, 7mm and in 30 cal. They are not bonded, but are a conventional type expanding bullet. I like Vihtavuori N150 or N550 for this weight bullet in the 8x57, but one of the 4350's will likely work fine. In a good strong 8x57, these will exit a 24" tube at 2550 or a bit more. I just checked my old Norma loading booklet, and they show 48 grains of old Norma 203 giving 2526. This powder is very close to IMR 4320 in burning rate. These bullets are quite effective on game, and expand reliably. Regards, Eagleye.