Here is my old Tanaka M870
I modded a RS wood fore-grip to fit and also did a slight mod to make a RS law-enforcement Remington top-folding stock.
Was an AMAZING gun that was heavy, loud and looked like a BEAST!
But I sold it because I could never get over the ejecting shells (which are very cool also) but I could never get the shell catcher to work proper. And when it did, it would get full very quickly...
Still one of my fav airsoft guns I have every owned or had the chance to use.