clandestine
AR-15 Savant
The HK21 charging handle is on the list, but my next accessory is a cheek pad. The recoil is not bad, but I do get a slap from her every once and a while.
I made one for my old PTR. Im in the process of making another for my G.I. I didn't like the Clip On Ones made for HK Stocks, but that's a personal preference.
I attached mine via industrial Velcro so I could remove it fast and use the Irons.