This is the ultimate FMJ bullet The (Total Metal Jacket). Speer uses Uni-Cor technology to take full metal jacket bullets to their highest level of evolution. They completely encase the lead core in a seamless jacket. Other FMJ bullets have lead exposed at the base, or have an accuracy-robbing second piece to cover the lead. Those bases can deform under pressure. These rifle bullets don't foul barrels as much as traditional FMJ bullets and keep airborne lead to a minimum.