Originally Posted by OMDonald
OP didn't state or imply replacing guns or other gear/supplies with a bow.
By very definition anything that goes in a BOB takes away from something else going in. There is a space/weight limit, and anything that takes up measurable space/weight counts towards that limit. Or simply adds to it and further burdens you.
He need not specify that the laws of physics still stand in order for them to do so.