I did the same thing to my 60. It's just a thing I'd do in airsoft, as you don't do much firing in the ****e in a fighting position and move alot. Most of the time I'd be running with it using it like a rifle, the old bipod is kind of a hindrance in that case, yet a pistol grip that instantly pops out the bipod, that is much more useful. I am kind of leery about putting too much downward force on the legs though. They don't look like they can take much.
Alright, new updates. I also re-finished the BE 870, and finished the fabrication of my precision tactical suppressor (long type). I have two masterkey systems, the Hardballer 870, and this BE 870. The BE 870 is much lighter, and easier to wield than the Hardballer. The suppressor was painted with dark grey, then polised/buff with a little shine to mimic the real thing.