The Swedish Military make a few items the dedicated bushcrafter will be familiar with - the firew steel and the mess kit being two of the most prominent, after all what self respecting outdoorsman with go without either (especially if you've read the swedish army survival manual!)
Like wise I think the 40l swedish military daysack my soon join the list. Why?? Why would you want a old fashioned external framed canvas and leather sack over a karrimor sabre 45??
Well dear reader the answers is simple - because its a old fashioned external framed canvas and leather sack!
Canvas can be treated with something like greenland wax and made rot and water proof - its repairable with a needle and thread - its hard wearing - wont melt around your campfire.
Leather can be treated with neats foot or other dubbin to make it supple and give is a rich chestnit brown, like canvas its repairable and easily adapted or replaced - leather unlike plastic buckles wont freeze and become brittle in extreme cold either!
External frame keeps the sack off your back whilst walking so avoids sweaty wet patches and chilling when you stop - the sack can be removed and the frame can be used on its own to gather fire wood or carry back sections of butchered game. It can also be used in such areas as first aid for example.
Volume - 40 litres in old money seems to be much more than 40litres in new money so you get a sack that will hold more - my sack easily holds all my kit for a weekend camp out!! But if your a kit junky there are strapped mounting points of the side and bottom for extra gear too!
Last but not least is the aesthetics - these sacks cry bushcraft - just wearing one makes you look like a long in the tooth bushcrafter who shuns all the fussy expensive modern bushcraft gear in favour of tried and test gear you know works!! And these come at a price you cant sniff at either - available from Bearclaw's trading post they even come with a free block of greenland wax and so are a fantastic bargain!