Okay, finally got it together with the Knoxx cop stock after letting the trigger group soak in mineral spirits a week or so (it was nasty). Lubed up with Mobil-1 synthetic 20W-50, my lube & protectant of choice for most long arms.
It cleaned up pretty darned well. I had gone after all gunk & rust earlier with a bronze brush & mineral spirits and did so again with a bronze brush & Mobil-1. It went from looking "neglected" (bad LEO, bad, bad!) to "well-used."
It points well, much better than my buddy's Mossy 500 with the Knoxx Spec Ops stock. I get a good line up with the receiver, bbl, & bead without having to move my head about. It is also much smoother after its thorough cleaning.
I still need to order the forearm and get some trigger group drift pins, as it came with a sidesaddle that does not work with the Cop Stock folded. The sidesaddle uses hex-head threaded screws that terminate in the sidesaddle. I'll also order a new mag spring to replace the partially-rusted original.
I must say that I was impressed at the 870's simple design & take-down. I had it tore down in minutes and only took a little first-timer fiddling to get it back together.
I'll get some more pics after the forearm comes in.
I have one of those Federal bird shot bulk pacs from Wally World waiting for it and I plan on patterning it with my Usual Suspects of buck shot. (Here's hoping it like Rem 2 3/4" 000 like my Rem 1100 does.)
One thing I have noticed about pump shotguns, especially those with shorter forearms to facilitate LEO use: my support arm goes WAY out there to get a grip on the forearm. I generally prefer a grip closer to the receiver.
