I've always thought that the Controlled Feed bolt actions were the most reliable.
@Elderberry Well,,they ARE reliable,but I won't say "most" reliable. ESPECIALLY not in a panic situation,where loading another round manually quickly and being able to shoot it are important factors. LOTS of people have panicked in stressful situations and "short stroked" a bolt rifle while trying to reload it,and ended up with an empty chamber.
Plus,almost everybody takes their eyes off the target trying to chamber another round in a bolt gun.
Neither are problems in a lever gun,plus they hold more ammo.
Hard to beat a Marlin 45/70 in bear country as a sling rifle while wandering around,though. Although if being attacked by a brownie,I would prefer a Huey Cobra or a Spooky C-130 gun ship.