This is what you're looking for:
https://www.amazon.com/Savior-Equipment-Warfare-Tactical-Backpack/dp/B07F9M8GH8
I have this Savior bag that i got off Amazon. It comes in several lengths depending on the lengths of your long guns. It has storage for 2 rifles, 2 pistols, mags, extra ammo and hearing protection.
https://www.amazon.com/Savior-Equipment-Warfare-Tactical-Backpack/dp/B07F9M8GH8
https://www.amazon.com/Savior-Equipment-Warfare-Tactical-Backpack/dp/B07F9M8GH8
Have a similar bag from Savior, good stuff