Remington has the worst finish out of an gun maker out there. I carried my Remington 1911 for one day and it rusted like a motherfucker, but my glock is good for months without cleaning. The internals arent bad, and it shoots great, but the "look at it too hard" is spot on. I would buy stainless if I bought remington.
Are we still talking about the 870? If so, it’s not available in stainless steel. The Marine Magnum is electroless nickel plated, inside and out.
I’ve got 3 870’s at my house and none have rusted on me. 2 started life as Police Wingmasters that came from NC State Corrections and arrived quite worn and beat up, but not rusty. Both have since been to Wilson Combat and back and been SBS’ed. One was re-parked by them and I had the other Cerakoted.
The 3rd is an older model Express model, back when they came with the ugly, plain wood with pressed “checkering”. No rust on her.
I don’t see any more rust on 870’s in the hands of my students than I see on other makes and models. Most non-Remington shotguns have aluminum receivers, so will show less rust overall.
All 870’s except the Police and Wingmaster models have a matte finish formed by bead-blasting then bluing. Not the most durable of finishes. Police models are parkerized and Wingmasters are polished and blued. I do not believe that Police Wingmasters have been produced in a long while, but it’s a bit irrelevant as the only differences between the two are the furniture, finish, and markings.