Just got one of these: Backpack Rucksack 55L | Trade Me
I wouldn't take it on a hardcore trip, but it'll do for carrying my sandwiches and cartridges down to the duck pond.
It's one seriously over-engineered bag with straps and buckles everywhere. I've taken most of them off. The pockets are all removable which is handy because the front pocket becomes a waist bag which I wanted for rabbit shooting.
It seems robust enough for casual use.
