I live in an apartment building in a dense neighborhood with street parking only. I often worry about people seeing me shuttling firearms in and out of my building as I don't want to draw unnecessary attention to myself, or make myself a theft target.
I've got a couple of 'break-down' cases for ARs that i like as they look pretty inconspicuous but I couldn't find anything like that for a shotgun. Sometimes I want to throw the shotgun in the car but I want to be able to carry it and stowe it with some concealment.
I did a lot of Googling and searching around Amazon and i couldn't find that anyone specifically made a product that was specifically marketed to this task. I figured something that looked less like a rifle case (big rectangle) would be better. I started searching for carrying cases based on dimension, rather that application, and I started to get somewhere. There were a lot of tripod carrying cases for pretty inexpensive and just from looking at the pictures they didn't look for "assuming."
I ended up going with a pair (yup, sold in pairs) of these Ruggard padded tripod cases, 42" in length, from Amazon:
Ruggard 42" Padded Tripod Case
They arrived quickly, thanks Amazon, and I checked them for fit. No problems. Shotgun fits in there with room. Enough room in fact that it's pretty easy to store extra ammo around the shotgun. The small zippered pouch on the side even works well for loose rounds, like the ones that come out of the gun when you unload it for transport.


Here you can see an 18" shotgun with a 12.5" LoP stock fits in with some room. Between the loose rounds in the zippered pouch(7th round went missing....) and the rest of the ammo in the case, that's 31 rounds of 12ga. At least as pictured. If I preferred I could carry less, or stick to shotgun cards and carry more, or keep a separate dump pouch with 50rds in it. It's whatever you want.
The bag is self feels cheaply made, the shoulder strap is non-padded and non-adjustable, but it works. Carried vertically and slung over the shoulder it goes from my shoulder down to about my knee and keeps pretty close to the body. Throw it in the back of the vehicle and off we go.