Also do you realize that Lapua makes SK, and it is just the same stuff off the same machines (except for the real high end Lapua), and probably did not test well enough to get the Lapua name on the box.
The SK and Lapua brands are made in the same factory, but not on the same machines. X-Act, Midas+ and Center-X may be the same ammo (sorted), but they are definitely not the same production as the SK rounds. Although, they may share some of the same components, powders, raw materials and even the same load recipe, the tolerance is much higher in anything with Lapua on the box. If you want to prove that to yourself, just weight the ammo. SK Std. Plus has a much higher weight distribution (1.3 gr. typically) than Center-X (0.3 gr.) and far less deviation in rim thickness. That isn't manufacturing variations from the same production line or tolerance gained by sorting after the fact. Companies don't sort individual cartridges by weight or rim thickness when they sort. They sort entire lots by test firing a sample of it.
Further, the SK brands are being offered in higher quantities than the Lapua brands. Ammo that is a byproduct of sorting is available in lower quantities than the parent brands (Team vs. Tenex), not the other way around. You might get small amounts of the Lapua brands being downgraded to SK, but not every lot of SK could be downgraded Lapua. No manufacturing outfit would ever tolerate such poor yeilds and that amount of sorting would be cost prohibitive.
Pistol King and Pistol OSP have much lower velocities than the SK pistol offerings or the Lapua Rifle offerings and Polar Biathlon has a is a different bullet profile altogether. That rules out sorting with those.
Also consider that the SK line was being sold and manufactured in Germany when the Lapua stuff was still being manufactured in Finland.