just snagged one on sale at midwayusa with a barrel for a dedicated upper. anyone use the special charge handle they sell? says its made to prevent jams, has a shallow channel and no hole for the gas key. I was thinking of filling mine with bedding compound, but for the $20 I may just get the cmmg one. also, tapco makes a plug that provides pressure to keep the conversion unit pressed forward. any thoughts? I need a FSB to mount the MOE hand guard or a free float, I haven't really decided on furniture yet. thanks