Don't overlook the Truglo SSX in that 870. I shot the Mag Blends with a SSX choke in my 12 ga. 870 last year and was getting 200 plus in the 10 at 40 yards. Nice even pattern too. I believe the SSX mics at .643. Sounds too tight i know, but the SSX works. I switched to a 20ga. this year and am getting 170's with the SSX using the Fed HW #7's. The SSX seems to be a great choke in a lot of guns for $30.00.