IDK this is a quote from mfg webpage:
PLEASE NOTE:
Will NOT work with .22 AR's without extensive modification to the rifle. The SSAR-15 is NOT a mechanical device. It does not perform any automatic functions, and it does not increase a rifles rate of fire.
The SSAR-15 is a rifle stock, and the muscular application of force to create forward movement of the firearm defines the will of the shooter to discharge each individual round of ammunition. Each discharge requires a separate decision by the operator to move the firearm back to a firing condition.
With the SSAR-15 installed – the firearm is still dependent on an actively engaged operator at all times; if the operator ceases to apply sufficient effort to move the firearm back to a firing condition; the firearm will immediately cease operating. The SSAR-15 is a non-mechanical device and will work as advertised with any rifle that meets the use specifications and is set up correctly, therefore returns on this item are subject to a restocking fee and our actual shipping cost.
ATTENTION - The installation and/or use of a Slide Fire Solutions, Inc. product - is a binding agreement that the purchaser assumes all risks associated with the use of said products, and releases and holds harmless Noble Firearms Inc, Slide Fire Solutions, Inc., Military Gun Supply, their affiliates, successors, shareholders, employees and representatives, from and against any liability, disability, death or loss or damage to person or property, whether arising from negligence or otherwise.