Like the title says - does Glock make a factory +2 magazine extension for the G21 mag? I know they make a factory +2 for the 9mm and .40 mags, but how about the larger frame Glocks. It would be sweet to be able to have a 15+1 G21. That would put it in the same field as a FNX45.
If not, does anyone know if any of the aftermarket extension or high capacity magazines are reliable?