Quoted:
CH139,
Your first photo is of the 18" barrel version. They look similure because the non-NFA Mossbergs use a differant mag tube then the NFA (in the stickman photo) version. Your second photo with the Surefire forend is a 14" "Compact" 590. Both models are 5+1 which gives them a very differant llok then a stock 870.
The Mossberg produced 18" breaching barrels for the 870 and the 500/590 are one piece barrels, The bore is about 15" with the last 3" as a stand off which is machined into the barrel when it is made. OAL is 18". The 16" NFA barrels are made the same way.
I had not known they used a different magazine tube. But they're both 5-shell tubes?
A friend sent me the pic below of his 590A1.
So, I'm thinking most of the above pics by
pezboytate are probably showing guns with 20-inch barrels.
Apologize for muddying the waters, I'm just all kinds of curious about this stuff.
So, as "civilians" we can get a gun like the one in the pic my friend sent me... 590A1 with 18+inch bead-sighted barrel. Does Mossberg sell the 590A1 with a 20-inch bead-sighted barrel (the one with the shorter magazine tube as in the mil pics)?