It is quite difficult to buy a sub-600 gram pack (@55 litre) ‘off the shelf’ for reasonable money. I have tried a number over the years and would not carry anything else. The ‘list’ below is not exhaustive but intended as a good starting point:
Gossamer Gear’s (now 54 litre http://gossamergear.com/g4-ultralight-backpack-all-bundle.html) ‘tried and true’ G4 lead the field (576 grams inc hip belt) US$150 and was my first ‘ultralight’ pack; (You can sew in some pieces of webbing to enclose carbon fibre arrow shafts for load transfer or, I find Big Agnes’ ‘Cyclone Chair’ (http://www.theultralighthiker.com/cyclone-chair/) underneath the pad works well) especially with the Airbeam pad as featured here: http://www.theultralighthiker.com/klymit-air-beam-inflatable-pack-frame-update/.
You could also try Gossamer Gear’s Gorilla which comes down close to 600 grams if you switch out the waist belt as I did:
Mountain Laurel Designs have an excellent contender with their Exodus pack (485 grams http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=25&products_id=103) at US$195. Certainly the lightest and most rugged ‘off the shelf’ model. I’m sure Ron will sew in a couple of pad holders or webbing tubes for carbon fibre arrow shafts if needed for a custom charge. He has his own air beam load transfer system though. I might also option the pockets in solid Dyneema as I have found the netting which many manufacturers use for their pockets to not like blackberries overmuch, but Ron has at least made the critical wear surfaces of these from Dyneema!
Granite Gear’s Virga 2 (54 Litre) 540 grams http://www.granitegear.com/virga-2.html US$139 is another fine option.
Terra Nova’s Quasar 55 is another option at 436 grams http://www.terra-nova.co.uk/packs-rucksacks-poles/all-packs/quasar-55-pack/ and US$320
Zpacks Arc Blast (595 grams http://www.zpacks.com/backpacks/arc_blast.shtml) $US315 looks a beauty and is pretty much the only one with load transfer, though I query if you are carrying less than 10 kilograms you need much load transfer. You can upscale to their Arc Haul in Dyneema (680 grams for 60 litres) if you want something completely bulletproof.
Zpack Blast (or Zero): Joe will still make you one of his ‘Blast’ packs (optioned from his ‘Zero’ range) – try the ‘Wayback Machine’ (https://archive.org/web/) to see what these were like. In 1.43oz/yd2 cuben a 58 litre ‘Blast’ weighs 235 grams (Yes!); 339 grams in 2.9oz/yd2 ‘Hybrid’ cuben material; (I can’t see how you can go past that 339 grams) & probably around 420 grams in 4.8oz/yd2 Dyneema. I have just weighed my (now 100% Dyneema) model at 430 grams including two shoulder pockets and two extra over the top tie downs.Della is still using her 235 gram model, but mine needed quite a lot of repair tape: I am rougher on my packs than she is, and mine has had a lot more use. Della rebuilt it for me here: http://www.theultralighthiker.com/backpack-repairs/ The original Blast in Hybrid/Dyneema with Pad sleeves for my chair and Sitlight pad is my choice. NB: Joe now calls this the ‘Zero’. Apparently Joe no longer does pad sleeves but has a lighter shock cord alternative at 6 grams (lighter) which will well suit an Air Beam pad (see above). Highly recommended. I option an oversize pocket one side for my tent. I have been using my Dyneema Blast for many thousands of kilometres now, and it it still as good as new. It weighs just on 300 grams with a pad sleeve and a tent pocket on one side!
or try a search at the top of the page using the word ‘pack’. I have many similar posts.
Some Other Hunting Related Posts (there are many more):