.30 accuracy?

[Edmond , DCB shooting]

Hi all ! from experience , I can say .30 L�¼ger is more accurate than most 9 mm, at least I never shot an ammo that was not. but with the correct ammo, 9 mm are equally accurate. should we say that there is more quality ammo in .30 than in 9 mm ? I could notice this phenomenon in Parabellum and SIG P 210 pistols.