The SP-6 munitions were developed by Yuri Folov and optimized for penetration through any type of conventional body armor, in fact SP-6 rounds can penetrate through 30 layers of Kevlar at 200m, through 2mm of steel at 500m or 8mm at 100m. In game terms these rounds are capable of tearing through any type of body armor and are better suited to be chambered in assault rifles like the Tunder S14 as they don't greatly enhance the accuracy of the weapon unlike the SP-5.