Anderson lower, SBA3 brace, Adams Arms 11.5” piston upper, with a SIG Romeo5. Other highlights, MOE-K grip, KVP Linear Compensator, MBUS sights (Pro up front for heat with gas block), and a nickel-Boron trigger group. Might swap the trigger for a Fostech Echo II, if all good when it comes back from Fostech (C/S is awesome with them). Only difference from picture is actually have an ambidextrous selector, opposed to one that had stripped threads.
Comes out to just under 26”, which is a nice setup to have just leaving NJ. My new truck gun, so I set it up to be used if there ever was an active shooter or another type of threat when I’m not working. The Echo trigger would be a nice addition... if it functions 100%. SIG red dot is good enough for what I need, with the battery life I’d want in this role. I do have a LaRue mount on order for it, in case I ever had to pull it from the gun. TLR-1 is one of my standard lights, and running Gen 2 PMAGs in it (straight 20 is the one in the gun for profile sake).
I wanted to stick in the over 10” range, mainly for velocity. I run two types of ammo; Hornady Critical Defense (73 grain) and M855. Hornady is in the gun, and have a four magazine pouch holding two Hornady and two M855. Also tossed an extra magazine of each in the center console. My theory... CD does well out of short barrels ballistically. Not too sure on hard barrier penetration, which I am sure on M855. If CD works well through barriers, I’ll dump M855 and go all Hornady... but too early to tell.
I considered a 9mm pistol, and probably will get a CMMG Banshee when we move over to Glocks... but only benefit is magazine compatibility and less noise. Personally, I rather a rifle round over a pistol round... but both likely would work.