If your looking to bowhunt from a box blind it will need to be much larger than a 4x4.
A 5x6 or 6x6 is more likely to accomidate a normal draw length all body parts included.

Been there, done that. I've got 2 4x5" and it is possible to draw on the 5' lengths, but they windows have to be pointed just the right direction for a shot.

And for all the naysayers- it does provide a decent wet / rainy day option.