M3, I was in Rockville and Poolesville last night on business. Little hunting there now, it's all Yuppie habitat and a cesspool of Liberalism(G).Deer all over, had Bambi in the headlights twice on Route 107.
Sporting shotguns have different needs than HD or slug guns,the famed versatility of shotguns are a bit overblown. Also....
A stock, out of the box, 870 is a HD weapon of incredible power and effectiveness. While the HD 870 here is accessorized like Joan Rivers, I could do good work with my bird 870, with an option list of a lengthened forcing cone,and a tweaked stock.In a crisis like that, if 4 rounds of 12 ga ammo and good training will not get you out of a jam, chances are a couple more rounds and a ghost ring sight won't either.
Stock fit is crucial, tho it seems using a stock on the short side isn't as egregious as using one that's too long. I'm a behemoth, 6'2", 240, 36 inch sleeve, and the factory stock works ok,I've reduced drop a bit and it shoots fine for me.Try a slip on recoil pad,right over the stock one, to lengthen the pull,it should add around an inch. If it works, you can have a good smith do a real stock extension.
Hope this helps...