9mm AR question....

[Mr. Joshua]

Which 9mm mag block will accept Colt 9mm AR mags?

[REDHORSE]

For Colt style 9mm uppers:

RRA 9mm AR15/M16 Magwell Conversion Block

Newest design with bolt hold open feature. Works with any magazine designed for the Colt 9mm AR15 including modified UZI magazines. Bolt hold open feature only works with factory Colt magazines (see below). Installs from the bottom of the lower and is held in place be an integral retaining pin. No modifications or fitting to your lower are required. This is the same conversion block used on the current Colt 9mm AR15.

Rock River Arms

[Mr. Joshua]

Thanks Redhorse!