, ▁allowing ▁higher ▁veloc ities ▁to ▁be ▁achieved ▁without ▁lead ▁depos its . ▁ ▁Jack et ed ▁lead : ▁Bul lets ▁intended ▁for ▁even ▁higher - vel ocity ▁applications ▁generally ▁have ▁a ▁lead ▁core ▁that ▁is ▁jack et ed ▁or ▁pl ated ▁with ▁g ild ing ▁metal , ▁cu pr on ick el , ▁co pper ▁allo ys , ▁or ▁steel ; ▁a ▁thin ▁layer ▁of ▁harder ▁metal ▁protect s ▁the ▁so fter ▁lead ▁core ▁when ▁the ▁bullet ▁is ▁passing ▁through ▁the ▁bar rel ▁and ▁during ▁flight , ▁which ▁allows ▁deliver ing ▁the ▁bullet ▁int act ▁to ▁the ▁target . ▁There , ▁the ▁heavy ▁lead ▁core ▁del ivers ▁its ▁kin etic ▁energy ▁to ▁the ▁target . ▁Full ▁metal ▁jack et ▁or ▁" ball " ▁bul lets ▁( cart rid ges ▁with ▁ball ▁bul lets , ▁which ▁despite ▁the ▁name ▁are ▁not ▁spher ical , ▁are ▁called ▁ball ▁am mun ition ) ▁are ▁completely ▁enc ased ▁in ▁the ▁harder ▁metal ▁jack et , ▁except ▁for ▁the ▁base . ▁Some ▁bullet ▁jack ets ▁do ▁not ▁extend ▁to ▁the ▁front ▁of ▁the ▁bullet , ▁to ▁aid ▁expansion ▁and ▁increase ▁le th ality ; ▁these ▁are ▁called ▁soft ▁point ▁( if ▁the ▁exposed ▁lead ▁tip ▁is ▁solid ) ▁or ▁h ollow ▁point ▁bul lets ▁( if ▁a ▁cav ity ▁or ▁hole ▁is ▁present ). ▁Ste el ▁bul lets ▁are ▁often ▁pl ated ▁with ▁co pper ▁or ▁other ▁met als ▁for ▁cor ros ion ▁resistance ▁during ▁long ▁periods ▁of ▁storage . ▁Syn th etic ▁jack et ▁materials ▁such