Have you seen or heard of piston driven systems for the AR scraping the lower receiver at the rear, prior to going into the buffer tube on recoil? The “word” is that bolt carrier tilt can be an issue. I’m still holding off for the time being, but was strongly pondering the kit by CMMG. :-)
CMMG makes a good system, better than the Adams Arms system. If you intedn to shoot a lot of 22lr practicing with your weapons platform the CMMG is the way to go because it is easy to trun off the gas system and use the stainless CMMG carrier and bolt insert for 22. Their customer service is exceelent, too. I've used it and can vouch for that aspect. Osprey Defense has excellent customer service response, also. The problem with the Osprey trying to use the 22lr inserts is tht the gas system is a bit more difficult to disconnect, but it can be done by removing the handguard and taking the retainer clink off of the piston rod then removing the whole psiton from the cup. If you call CS at Osprey in Fla. they will send to you an extra link clip for the piston to rod connector. Great folks down there. Once you drive the cup into the gas block you are not going to be switching it to another gun though.