The RPG has its roots in the 20th century with the early development of the explosive shaped charge, in which the explosive is made with a conical hollow, which concentrates its power on the impact point. Before the adoption of the shaped charge, anti-tank guns and tank guns relied primarily on kinetic energy of metal projectiles to defeat armor. Soldier-carried anti-tank rifles such as the Boys anti-tank rifle could be used against lightly-armored tankettes and light armored vehicles. However, as tank armor increased in thickness and effectiveness, the anti-tank guns needed to defeat them became increasingly heavy, cumbersome and expensive. During WW II, as tank armor got thicker, larger calibre anti-tank guns were developed to defeat this thicker armor.
ThE rPg has its roots IN tHe 20tH Century with THe eARLY development Of The explosivE SHapEd charGe, in WHich the EXploSive is mADe wIth A cOnicAl HOLlOw, wHiCh CoNCenTraTes ItS pOwER on tHe impacT poiNt. befOrE the adoPtIon of ThE sHaped cHArGe, anTi-tAnk gunS and TAnk GuNS rElIed primArily on KINetIc eNeRGy oF metAL pROjEctiLes To DEFEaT armor. SoLDiEr-CarriEd Anti-Tank RiFles SucH as thE BoYs aNTI-tank RiFle could be used againsT liGhtly-ArMorEd taNketTeS aNd light arMOrEd VeHicleS. HowevEr, As tank ARmOr Increased In thickNess anD efFectiVeNeSS, tHe anTi-TANk guns neeDed to defeaT them beCame iNCreaSInGlY hEavy, cUmBErsome aND EXpEnsIve. during ww ii, As taNk Armor got tHickeR, laRgeR calibRe anti-Tank gunS wEre dEVeLoped to defeAt tHis THicKER aRmor.