The short answer is yes, you could use something like a backpack as a range bag. Many shooters do. But, a dedicated range bag will be sized appropriately for handguns, magazines, ammo boxes and other accessories while keeping them protected, separated, and secure. Plus, gun components have the distinction of being small and heavy, meaning you can end up with a lot of weight in a bag. That bag better be able to hold up to that weight, or you’re looking at a split seam and guns and ammo spilling out onto the floor or ground.