Thread: "Shooting" day pack vs "normal" day pack

So I've never owned a dedicated shooting/hunting/tacticool day pack before as I've just used a pretty stand small 18L bag for my casual shooting and short hunting trips.
I've had pretty good success the last 10+ years, but one of things that's always bugged me is that it's never rigid enough to shoot off unless I unnecessarily cram it with stuff.

For those of you with these types of packs, do they tend to be more rigid or offer any obvious benefits over your backpack.
Also keen to hear any recommendations that I could look at before buying to decide if it's what I'm after.