I am working with a customer on what will eventually become the SM-2, a pistol grip 870 that is awesome.  Same high quality components, but a Speedfeed pistol grip. If you are thinking about adding a pistol grip to your shotgun there area a few things to remember.  The first is that you must have an barrel length of at least 18″ and the overall length of the gun must be 26″.  This last one is a little known fact, but ATF is serious...