▁too ▁complicated ▁to ▁produce . ▁ ▁The ▁soft ▁lead ▁M ini é ▁ball ▁was ▁first ▁introduced ▁in ▁ 1 8 4 7 ▁by ▁Claude - Ét ienne ▁M ini é , ▁a ▁captain ▁in ▁the ▁French ▁Army . ▁It ▁was ▁another ▁improvement ▁of ▁the ▁work ▁done ▁by ▁Del v igne . ▁As ▁designed ▁by ▁M ini é , ▁the ▁bullet ▁was ▁con ical ▁in ▁shape ▁with ▁a ▁h ollow ▁cav ity ▁in ▁the ▁rear , ▁which ▁was ▁fitted ▁with ▁a ▁small ▁iron ▁cap ▁instead ▁of ▁a ▁wooden ▁plug . ▁When ▁fired , ▁the ▁iron ▁cap ▁would ▁force ▁itself ▁into ▁the ▁h ollow ▁cav ity ▁at ▁the ▁rear ▁of ▁the ▁bullet , ▁thus ▁expand ing ▁the ▁sides ▁of ▁the ▁bullet ▁to ▁g rip ▁and ▁eng age ▁the ▁rif ling . ▁In ▁ 1 8 5 1 , ▁the ▁British ▁adopted ▁the ▁M ini é ▁ball ▁for ▁their ▁ 7 0 2 - inch ▁Pattern ▁ 1 8 5 1 ▁M ini é ▁rif le . ▁In ▁ 1 8 5 5 ▁James ▁Bur ton , ▁a ▁mach in ist ▁at ▁the ▁US ▁Arm ory ▁at ▁Har per ' s ▁Fer ry , ▁West ▁Virginia ▁improved ▁the ▁M ini é ▁Ball ▁further ▁by ▁elimin ating ▁the ▁metal ▁cup ▁in ▁the ▁bottom ▁of ▁the ▁bullet . ▁The ▁M ini é ▁ball ▁first ▁saw ▁w ides p read ▁use ▁in ▁the ▁Crime an ▁War ▁( 1 8 5 3 - 5 6 ). ▁R ough ly ▁ 9 0 % ▁of ▁the ▁battle field ▁cas ual ties