Steve-not sure what you're looking to do with it, but I've used a number of different packs over the years and a few years ago settled on a Seek Outside, Revolution Fortress.
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Light - about 4 lbs.
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Waterproof!!
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Large - with the added outside pouch that you can use as a daypack, almost 8,000c.i. total.
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Comfortable. The heaviest thing I've hauled with it is a brown bear hide and skull. They are notoriously heavy, but it handled the load well.
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Probably can get an average-sized moose quarter in the bag itself, but can also strap it to the outside or take the bag off and strap it to the frame.
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The frame is very small, and it's hard to tell that's it not an internal frame pack. in fact, it "wears" like an internal frame.
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An open pouch, low on both sides of the main bag, for water bottles, spotting scope...
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It's light enough and comfortable enough that I use it for everything.