Among the Thumper rounds requiring the use of the AR-10 platform due to their larger cartridge dimensions are the .45 Raptor, .50 Thumper, .50 Razorback, .50 Krater, .500 Kratos/Enforcer, .500 Auto Max, .500 Phantom, .500 Whisper, .510 Whisper, .510 Snipe-Tac and the .510 Winchester Short Magnum cartridges. This wide spectrum of calibers developed until today along the line of the Thumper concept ranging from Wildcat cartridges to commercially available rifle/cartridge combinations and to calibers with approval through SAAMI or C.I.P. suggests that this field has not yet produced optimized solutions and is still subject to Engineering optimization.