I have a 20 gauge 500,I have noticed the various foreends for the 12 ga are plentiful but there is not much choice in the 20....has anyone here had success fitting a 12 ga part to a 20 ga shotgun?.I realise they will be a different size but as I am a machinist and have access to a lathe and mill etc I can easily make an adapter if that is feasible,just wanting to know if others have tried this route......