I have a few S&W .22 suppressor adapters that fit the 422+622 models (should fit others though). I bought a few but never followed through with the suppressor. Pd $35 each but will take $23 each shipped. Paypal is okay.
1/2"-28 threaded adapter for Smith & Wesson 422/622/2206/2214. This replaces the barrel nut and allows attachment of suppressors and other accessories with 1/2"-28 thread. Designed for use without the lock washer that is used in conjunction with the original nut. Includes knurled thread protector. Allen wrench required for installation and removal (Not included) Recommended installation torque is 25 inch pounds. Stainless Steel. Made in USA!