...that shoot well, have an involved sorting system for CP pellets usually for both weight and head diameter.
Of course they do this for the best pellets and to segregate the pellets into a system of lots, (competition, practice, plinking, etc.)
And I would think there's a better than average chance that the sorting method isn't as effective with other brands.
So yep, the numbers don't lie but there's more to it than meets the eye.
I would be curious to know how a box of CP's breaks down into what a shooter considers "match" grade for his rifle.