I've got a Ciener Conversion Unit for AR15 that I sent to Spikes while I was waiting on my upper. It comes with the chamber adapter for .223 and a Spikes chamber adapter for dedicated .22 barrels. Also comes with a unused 10 round Ciener mag. 400 rounds put through it. Runs great in my 11.5" using the .223 adapter. Runs even better with the dedicated .22 barrel. This would be a perfect unit for you guys building your own dedicated .22 uppers. Includes plastic box and manual.
$190 with Spikes adapter $165 without. shipped CONUS.
IM for payment