Polymer syrup of polymethyl methacrylate and polystyrene reinforced with 2% non settling nanoalumina particles was prepared by dual initiating system containing benzoylperoxide (BPO), azo-bisisobutyro nitrile (AIBN) and dimethylaniline (DMA). Nanoalumina particles were prepared using autoignition of aluminum nitrate and urea. Nanoalumina particles show the tendency of agglomeration in the polymer matrix because of the presence of hydroxyl groups on its surface. To get better dispersion in polymer matrix, the alumina surface was treated with methacrylol isocyanate, synthesized by the reaction of methacrylol chloride and sodium azide in the presence of dry benzene at 0 degrees C. The polymer syrup prepared this way was applied between two PMMA sheets of 10 cms x 10 cms x 2 mm dimensions each and the composite thus prepared was tested with Bullet Firing Machine as well as Vertical Drop Weight Impact Testing Machine. The impact strength measurements of two plates composite using both these procedures showed that the impact resistance was found to double in case of nanoalumina. The composite of ten layers and of eleven layers was further tested by 0.32 IOF revolver and Sub Machine Gun Carbine 9 mm 1A1 respectively from 10 m distance which produced an ordinary indent with no penetration.