5.11 gear is all overpriced and also a big red flag that you are carrying guns and knives. Do not buy 5.11. Do not carry it. Dont give it to friends if you value their lives.
Cheap looking gear from Walmart draws the least attention and makes you less of a target. Failing that, REI stuff is good quality but expensive.
https://www.rei.com/c/hiking-backpacks
they do not sort by capacity. Sorry.
Carhart is an excellent brand, but again not cheap.
https://www.amazon.com/Carhartt-Backpack-Unisex-Crossbody-Travel/dp/B08J7J8WMV
All the products I've had from them are excellent.
Sportsmans Guide carrys nice products, but most of them reek of TactiCool and again, not cheap.