Living in the communist republic of California I use this fixed mag adapter to convert my scary "assault weapon" to a fixed mag non assault weapon. The device works very well and feeds completely reliably, but has had one problem: The small part that holds the handle that allows the follower to be pulled down and locked while loading has broken twice so far. The spring for the AR-10 unit is quite strong and I feel that the part is too weak. I have not had this problem with my AR-15 compmag units. Hopefully this part will be re-designed in the future.