▁prevent ed ▁fighting ▁from ▁a ▁h ull - down ▁firing ▁position . ▁In ▁addition , ▁the ▁use ▁of ▁riv et ed ▁h ull ▁super structure ▁arm or ▁on ▁the ▁early ▁versions ▁led ▁to ▁sp alling , ▁where ▁the ▁impact ▁of ▁enemy ▁shell s ▁caused ▁the ▁riv ets ▁to ▁break ▁off ▁and ▁become ▁project iles ▁inside ▁the ▁tank . ▁Later ▁models ▁were ▁built ▁with ▁all - w eld ed ▁arm or ▁to ▁eliminate ▁this ▁problem . ▁These ▁less ons ▁had ▁already ▁been ▁applied ▁to ▁the ▁design ▁and ▁production ▁of ▁the ▁M 4 . ▁ ▁The ▁M 3 ▁was ▁replaced ▁in ▁front - line ▁roles ▁by ▁the ▁M 4 ▁Sh erman ▁as ▁soon ▁as ▁the ▁M 4 ▁was ▁available . ▁However , ▁several ▁special ist ▁vehicles ▁based ▁on ▁the ▁M 3 ▁were ▁later ▁employed ▁in ▁Europe , ▁such ▁as ▁the ▁M 3 1 ▁arm ored ▁recovery ▁vehicle ▁and ▁the ▁Canal ▁Def ence ▁Light . ▁ ▁Eastern ▁Europe - ▁Soviet ▁Service ▁ ▁Begin ning ▁from ▁ 1 9 4 1 , ▁ 1 , 3 8 6 ▁M 3 ▁medium ▁t anks ▁were ▁sh ipped ▁from ▁the ▁USA ▁to ▁the ▁Soviet ▁Union , ▁with ▁ 4 1 7 ▁lost ▁during ▁sh ipping ▁( when ▁they ▁went ▁down ▁with ▁their ▁transport ing ▁vessels ▁which ▁were ▁lost ▁to ▁German ▁sub marine , ▁naval ▁and ▁aer ial ▁attacks ▁en ▁route ). ▁These ▁were ▁supplied ▁through ▁the ▁American ▁L end - Le ase ▁program ▁between ▁ 1 9 4 2 ▁and ▁ 1 9 4 3 . ▁ ▁Like ▁British