We demonstrate volume holographic recording in silica-nanoparticle-dispersed methacrylate photopolymers with reduced scattering loss as low as 2%. This is made possible by use of 13-nm silica nanoparticles. As a result a net diffraction efficiency near 100% is achieved for a transmission volume hologram of 45-microm thickness. Grating buildup dynamics are measured for various nanoparticle concentrations, and the effects of nanoparticle size on refractive-index modulation and polymerization shrinkage are also evaluated.