I carried a "pistol" then an sbr w/ a detached, but quick mount, suppressor for more than a year and will be carrying again very soon.
Vertx Gamut Plus, a
Law Tactical folding adapter, your choice of SBR setup (I prefer a piston setup as they work far better in the 7-9inch area in 5.56. If you are going to go 300blk, then a DI system will work fine.
I am going to be transitioning to a bigger bag (slightly bigger) so I can carry my SBR w/ PDW stock on it in a center-mount style - arc'teryx khard or lbx make a nice one...might even get the new
5.11 Ignitor,
Covrt boxpack or
M4 shorty backpack.
Few things to consider:
You won't just be carrying a rifle/pistol rifle/sbr w/ a can on it.
You'll be carrying mags, IFAK/Trauma kit, pistol reloads, gloves, ear pro, TQ's, etc etc. So plan accordingly.
I'll be doing a review of the Vertx Gamut Plus soon, I've been busy and have not gotten around to it.