Introduction介绍TounderstandfullythehistoryoftheMP38andMP40,weneedtoreflectingeneralontheunderlyingprinciplesofsubmachineguns(sMGs).Inthemodernworld,therationalebehindsMGshasbeenslightlylost,atleastinofficialmilitarycircles,owingtotheubiquityoftheassaultrifle,aweaponthatmanagestostrikeaneffectivebalancebetweentherangeofafullpowerrifleandthesuppressivefireofansMG.Yetifwedialbacktimetothebeginnin...