▁weapons ▁were ▁mounted ▁to ▁give ▁the ▁t anks ▁ade qu ate ▁cap ability ▁in ▁firing ▁both ▁anti - person nel ▁high ▁explos ive ▁and ▁can ister ▁am mun ition ▁and ▁arm or - p ier cing ▁am mun ition ▁for ▁anti - t ank ▁combat . ▁The ▁M 3 ▁differ ed ▁slightly ▁from ▁this ▁pattern , ▁having ▁a ▁main ▁gun ▁that ▁could ▁fire ▁an ▁arm or - p ier cing ▁project ile ▁at ▁a ▁velocity ▁high ▁enough ▁for ▁effectively ▁pier cing ▁arm or , ▁as ▁well ▁as ▁deliver ▁a ▁high - expl os ive ▁shell ▁that ▁was ▁large ▁enough ▁to ▁be ▁effective . ▁Using ▁a ▁h ull ▁mounted ▁gun , ▁the ▁M 3 ▁design ▁could ▁be ▁produced ▁faster ▁than ▁a ▁tank ▁featuring ▁a ▁tur ret ed ▁gun . ▁It ▁was ▁understood ▁that ▁the ▁M 3 ▁design ▁was ▁fla wed , ▁but ▁Britain ▁ur g ently ▁needed ▁t anks . ▁A ▁draw back ▁of ▁the ▁spons on ▁mount ▁was ▁that ▁the ▁M 3 ▁could ▁not ▁take ▁a ▁h ull - down ▁position ▁and ▁use ▁its ▁ 7 5   mm ▁gun ▁at ▁the ▁same ▁time . ▁The ▁M 3 ▁was ▁tall ▁and ▁room y : ▁the ▁power ▁transmission ▁ran ▁through ▁the ▁crew ▁compart ment ▁under ▁the ▁tur ret ▁basket ▁to ▁the ▁g ear box ▁driving ▁the ▁front ▁s pro ckets . ▁Ste ering ▁was ▁by ▁differential ▁bra king , ▁with ▁a ▁turning ▁circle ▁of ▁. ▁The ▁vertical ▁vol ute - spr ung ▁susp ension ▁( V V SS ) ▁units ▁possessed ▁a ▁return ▁roll