One issue you will have is the bullet going supersonic. Typically, you want a 5" or shorter barrel to keep .22LR subsonic, though my 10" with Aguila 38gr. subsonic loads is still VERY quiet. I don't think the 14" would keep that load subsonic, as I know my 18" 77/22 does not. But, if you already have the suppressor, might as well spend a few dollars to get a barrel you like threaded as it will be a sound reduction no matter what. I looked at the Tac 65 initially, but went with the Spectre because I liked that it was steel rather than aluminum and could be disassembled for cleaning. Were I to do it, again, I would probably go with a Liberty Cans Sparrow, not because of any shortcomings I have found in the Spectre, but because I think the Sparrow is comparable at a lower price and a bit easier to take apart. The Spectre will handle .22LR/Mag, .17HMR, and 5.7X28mm, though I will never bother threading my Five-seveN.