I had this on a SBR I built awhile ago. Think I ran several mags through it without issues using a 10.5" Ballistic Advantage barrel and then put the rifle in the safe.
These did not come with a bolt, etc. - just the carrier and piston parts. It uses a standard cam, cotter pin, bolt (less rings) and firing pin. .750 diameter gas block.
Decided to change the setup since I am bored.
$150 shipped legal lower 48. F&F P or USPS MO.
Thanks for looking.
cool item guys
Still can be yours