I first put it on there because the "pumping" motion of shotguns hurt my left wrist...I broke it years ago and it still causes me grief. I bought a Promag piece with three rails so I could attach the Tapco grip, it fits ok but not as well as the stocker, there was a bit more slop than I wanted so I took it off.That's pretty neat! Why did you go against the front grip?
I bought this one here:What type light mount is that? Does it stay put when firing?