Jepp, it is one of the older ones, in fact, if I rembere correctly, it is one of the oldest ones before decomissioning in the late 1990ts and early 2000. The one that is on the picture is a part of the swedish armed forces m/59- system (m standing for modell and 59 for 1959) which was the standard field system for all service personell up untill 1990 when the m/90- system was comissioned slowly. The specific type that is on the picture (with the handle on top of the bag) was originaly used by the Air Force and the Navy. The Army version comes in a slightly smaler sack, without the hande on top and a ludicrisly small zipper (than one never could get open when it was very cold and you realy wanted to get in to your sleeping bag). Sleeping bags where however not standard equpiment for most of the armed forces before 2004 when the new Solider 2000- system and the MARKUS- system was released. Yes, it is heavy, and yes, it conains somekind of syntetic cotton that has a tendency of getting damp and wet, as Swede pointed out (or should I call him Brother in Arms, if I may

) It is not the current, standard version that the swedish armed forces uses. The new version is a sleeping bag system concisting of a inner sleeping bag, a outher sleeping bag, a sleeping bag cover and a bivye- sack called The Maggot. The enitre new sleeping bag system cost aroud 5000 SEK each (C. 450 Sterlings). The new system is great but very hard to track down as a civilian (I have noticed...).
When it comes to temperatur range the manuals actually does not say, but I have used it in service down to around minus 15- 20 Celsius without any major problems, but I would say the the comfort temperature is in the minus 5 to plus 15 Celsius. The only problem that I wound with it was that since there is a lot of cotton in it, it gets damp very qickly. Keep it in a bin liner bag when you have it in your back pack and turn it in side out when you are drying it.