Will Glock 30 10 round mags fit a

slinger

Glock 21? TIA

drobs

No they are too short.

NeoBlackdog

The 21 will fit the 30 but not the other way around. 30 mags are shorter.

drobs

Note lots of custom smiths out there a cutting the frames on Glock 21's down so they will take a Glock 30 10rd mag.

Here's an example:

http://www.bowietacticalconcepts.com/pictures.html

Robar also offers this service:
http://robarguns.com/custom-weapons/handguns/custom-glocks/

While not cut down I think this place does some some fantastic grip reductions:


http://www.weaponworx.com/