Hazard4 makes a couple that might work. I've had a Battle Axe for a while. It fits an AR, a pistol and assorted mags, etc.
https://www.hazard4.com/bags/ccw-bags/dropshot.html
https://www.hazard4.com/bags/ccw-bags/civilian-battle-axe.html
https://www.hazard4.com/bags/ccw-bags/dropshot.html
https://www.hazard4.com/bags/ccw-bags/civilian-battle-axe.html