Sig MPX 10rnd vs 20rnd Mags

[DocMedic]

I'm just curious, I see that the 10 round MPX magazine uses the same body as the 20 round MPX magazine, so I was wondering if someone that might have one or has first hand knowledge is what limits the mag to 10 rounds? Is it the spring like how the 9mm M&P 15 round mags are setup, or is it something to do within the body of the mag, or follower.

[MAP]

A friend has an MPX. His 30 round mags was riveted to allow on 10 rounds to be loaded.

Mike

[Rooskibar03]

You didn't stock up before the ban?

Ive seen magazine blocks that keep you from loading more than 10. They could be glued in place for a permanent fix.