So I started out with the CMMG kit that you drop into a regular AR upper. Wasn't happy with the accuracy.
So I got one of these:
We’ve combined a RTB stainless steel .22LR bolt group with a .22LR 16” lightweight pencil barrel to provide everything you’ll need for converting your upper to a dedicated .22 long rifle format in one convenient package. The barrel has pencil Profile and a 1:16” twist with a ½”-28 TPI muzzle thread
www.righttobear.com
And paired it with a slickside upper. With the pencil barrel it's incredibly light weight but honestly you can buy a Ruger 10/22 for what it costs to build the upper. And then you need the dedicated mags, too.
Runs GREAT! Was a lot of fun during the suppressed shooting hour at the Full Auto Frenzy this year. We went through a LOT of .22 during the hour...