SFW skeet has some 1kg of copper tantalum probably in EFP, going at 1km/s or slightly faster, BONUS is probably heavier because BONUS skeet is heavier than SFW skeet
more precisely, BONUS skeet is 6.5 kg while SFW skeet is 3.4 kg
tantalum EFPs, used when diameter is a limitation, can punch through its own diameter of RHA. diameter of skeets is in range of 130mm, and top armor of tanks can have anywhere between 30 and 70mm of thickness, rarely more, so there's some safety factor included