What made you decide to buy an 870 Express after all? Seemed like you weren't interested.
Also, bought this a couple days ago and should be here later today:
Stag Arms 3GHL complete upper with 18" fluted & freefloated heavy barrel. Maryland requires all AR-15s sold or made after 2013 to be HBARs so I figured I might as well build off the inherent advantages of a heavy barrel. I'm not crazy about that compensator on the end but it comes for free and I can always unscrew it and put something else on, maybe a suppressor once the Hearing Protection Act passes in a few months and it's not such a pain in the ass to buy one. Also, the picture isn't flipped, that is indeed a left-handed receiver. I have to shoot southpaw because of my left-eye dominance and messed up right eye and I'm sick of hot brass and sometimes GSR hitting me in the arm & face like my Keltec does.
Still waiting on my ambi 80% lower to get here, gotta get my cousin to help me machine it into a 100%, and then I have to buy all the other lower parts for it like a stock, trigger, and a few specific Southpaw-specific parts like the Norgon Ambi-Catch and an ambidextrous safety.