Yes a shameless plug for CMMG. I just got a complete upper from them, excelent product and service and fun
. I decided on a dedicated upper because I had tried a cousins action assembly and it jammed so much it wasn't worth shooting and not accurate. I don't know about the CMMG .22 action aasembly, but their other products are first rate.
The upper uses the same charging handle, forward assist and spring loaded ejection port cover like on my .223 upper. The CMMG upper fit right on my Bushmaster lower. The upper is an M4 style, no front or rear sights. I put a VORTEX SPARC red dot on it and a VLTOR adjustable stock, did I mention FUN.
Fun, handy little gun, got a lynx earlier this week with it. Now my wife wants one.