  We use simultaneous Swift and RXTE observations of the black hole binary GX
339-4 to measure the inner radius of its accretion disk in the hard state down
to 0.4% L_{Edd} via modeling of the thermal disk emission and the
relativistically broadened iron line. For the luminosity range covered in this
work, our results rule out a significantly truncated disk at 100-1000 R_g as
predicted by the advection-dominated accretion flow paradigm. The measurements
depend strongly on the assumed emission geometry, with most results providing
no clear picture of radius evolution. If the inclination is constrained to
roughly 20 degrees, however, the measurements based on the thermal disk
emission suggest a mildly receding disk at a luminosity of 0.4% L_{Edd}. The
iron abundance varies between roughly 1-2 solar abundances, with the i=20
degrees results indicating a negative correlation with luminosity, though this
is likely due to a change in disk illumination geometry.
