12-30-2019, 05:16 PM
How much are you willing to spend on building an upper?
A standard m4 upper receiver, criterion barrel w/bolt, and an ALG handguard would be my choices for a basic but high quality grendel upper.
A standard m4 upper receiver, criterion barrel w/bolt, and an ALG handguard would be my choices for a basic but high quality grendel upper.

