APX 21rd Mag Length

[JoeTom]

So I'm playing around with my APX in Carry Optics and wanted to make sure the factory 21rd mags were legal. I thought it might be a good time to buy a gauge since I'm committed to the sport. I bough the EGW mag gauge and stuck my APX mag in. As you can see, it's not a flush fit. I can't push the mag down any further without damaging the mag tube. Should I start looking for shorter extensions or is it close enough?

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