I never figured out why the 7mm has'nt caught on as good as the others. I know the reason that saums are falling off is because they would'nt let no one else chamber them because they thought they were really on to something. Then the wsm came out and they immediatly sold rights to other companies. All those sales put the saum on the back burner. They're equal cartridges, though the wsm shows slightly higher velocity, which I think was a marketing play, since you cant get more out of one than the other handloading. I might sell my saum sometime and get a 270wsm. I think i'd like one, maybe a 300 wsm.