The hypervelocity impact limit, V-50, of alumina/fibre-reinforced plastic (FRP) target materials was studied with different adhesive layer thicknesses and two kinds of FRP. A high-speed camera was used to analyse the perforation phenomena of target materials. In addition, the dishing and bulging extent of FRP as a rear material were investigated using a digital planimeter from a series of high-speed photographs during the perforation of a projectile. In the case of the same adhesive layer thickness, the target material with more ductile FRP (A type) absorbed more impact energy than that with less ductile FRP (B type). In both target materials, the highest V-50 was obtained at an adhesive layer thickness of 1.3 mm.