We might call the 7-rounders "New York Style" mags! Post the flippin' S.A.F.E. Act, unless one is at a sponsored event at the range, seven rounds is the max for loading any magazine.
I don't know what the double-stack guys do--ten rounds is the legal capacity for any mag since this executive action went into effect.
All mags of greater capacity are by now supposed to have been destroyed, permanently modified to hold the legal limit or fewer, or turned in to a dealer for sale/shipping out-of-state.