I'm not much of a wing shooter. But didn't even know they'd bought mag limits in, in NZ.
The brits are limited to two or three (side-by-sides or o/u's being basically not considered as firearms, and everyone's allowed one or ten, historically.)
And I think they allowed the pumpys one more, for whatever reason.
Gotta be a bit careful with tube-mags, those springs can go a fair distance, inter-dimensional even, if you don't put em back together properly. (Don't ask how I know)