Has any mainstream or SOT Mfg. tried the H&K type roller locking mechanism on a modified AR upper? I think the standard upper dimensions and a revised barrel extension is feasible for this action type. Ha ha ha, imagine G3 reliability giving AR modularity. This should be reliable from 7.5" PDWs to 24" SPRs. I would love to see this system come to reality . . . A true free floated barrel, a clean breach area, cheaper to manufacture and does not change any aspect in accessorizing. PS: May disadvantage reloaders due to the requirement of a fluted chamber.:embarassed: Wanna kill these ads? We can help!