When I was match shooting, Compass Lake built a dedicated 22LR upper for me. Without pulling the charging handle, You can't tell it from an A2 .223 AR-15. The charging handle has a shorter stroke and when the dust cover opens, the bolt looks different. They furnish it with a Douglas 1:16 match barrel. The magazine are M261 military conversion magazines which slip inside a 20 round AR mag. The mags look authentic, too!
It's accurate and reliable! It's a bit pricy, though.