For my many solo canoe expeditions in the Arctic Barrenlands, in Barrenground Grizzly country, I chose the 12 gauge pump shotgun with short "deer" barrel. I did alot of hiking on the barrens on these trips.
Yours truly showing carrying my shotgun:
Shotgun: Remington 870 Wingmaster 12ga.
Barrel: Remington's deer barrel, smooth bore with Remchoke system. Remchoke used is the smooth bore because of the multi-ammo selection I use: Rifled slugs, SSG, cracker shells, and rubber slugs. (Should I want to change the system to using just slugs, I would install the rifled Remchoke and use sabot slugs).
Sling: Sporting goods leather sling, nothing special. Front swivel is an Uncle Mike's adapter for the magazine screw cap. Rear swivel I installed in the usual bottom of the buttstock position. However this does dig into my back, so one of these days I need to install a flush cup QD swivel mount on the side of the buttstock, which should improve the carry comfort by flattening how the shotgun sits on my back. I also plan one day to upgrade the sling to a more adjustable model for different carry options.
Note also the bear spray on my right hip. In my pocket I have pen launch bear bangers.
This is the transport setup:
The camo inner case is a floating shotgun case, but it is not waterproof. In the canoe that case goes into the Kolpin dry bag case. In camp the shotgun is always out of the cases. The uncased gun goes into the tent with me for sleeping.
Ammo sleeve on the buttstock for reloads if I need them, but also for a selection of slugs, SSG, crackers and rubber slugs. The white hull round is a rubber slug. In my later trips I culled out the cracker shells because I use pen launched bear bangers.
IMO the 12 gauge pump shotgun with a relative short deer barrel is a versatile and reliable bear self defense system. This old 870 (1970's vintage) action is very smooth and reliable.
In the Barrens one is literally surrounded by grizzlies, although at low densities.
The photo above (location: Contwoyto Lake, Burnside River, Nunavut), shows a typical griz excavation of Sik-sik (Arctic ground squirrel) burrows. This was near my campsite.
This one below is a relatively fresh griz excavation of sik-sik burrow beside my campsite. As you can see the clods of turf have been peeled back not too long ago. In the Barrens Griz are all over the place. One has to learn how to stop worrying in order to sleep at night, inside the tent where you cannot see anything,....but you sleep with both ears open!
My Barrens solo trip durations are typically 30-45 days, and griz sightings happen every trip. Its been a while since I have been on the Barrens. I really miss it.