Here is some uncertainty. I think that in papers You have read was mentioned the percentage by volume not by mass. That is 6% vol is close to 40 % by mass (if density of polymer matrix is close to 1 g/cm3).
You should remove PVP capping agent to make conducting. The loading AgNPs in the composite can be increased more as Liliya suggested. Try to get maximum loading into the composite.
This paper might give you some insight about using hybrid filler to increase dispersion. Please kindly have a look. https://www.researchgate.net/publication/331173157_Polymer_Nanocomposites_Having_a_High_Filler_Content_Synthesis_Structures_Properties_and_Applications