I'd go with the 870 with the 20" cyl. bore barrel- no sights-and buckshot all the way, no slugs. Also, my retired neighbor, from the MSP- uses this same weapon yet today, and his has 3" chambers, but he told me that the MSP (Michigan State Police) armorers did a test with 3" slug loads over 2.75" slug loads, and found more feeding problems with the 3" and none with the 2.75" loads- "front heavy- makes them "tip" a bit at times. I am not sure if this caveat applies to 00 loads or not--You can also read, if you like, Hemingway's last posthumously publish novel- True At First Light and see how he used his full choked 12 gauge Model 12 with No. 8 birdshot loads to dispatch a wounded "Chui" in a mangrove tangle in Africa-- One advantage the Model 12 has, at least the pre-1970 remaked "Y" series which changed the trigger mechanism- you can "slam-fire" an older Model 12, not sure about the Rem 870- But I'd sure as shootin' want more than 2 shots from a non-ejector double gun in a SHTF scenario with a bear-CQC style--The 870 pumpgun is foolproof-
