FMJ's Ultimate Bullet. Uni-Cor™ technology is used by Speer to make full metal jacket bullets to the next level of innovation. They completely encase the lead core in a seamless jacket. Other FMJ bullets have lead exposed at the base or a second piece to cover the lead that reduces accuracy. Under pressure, the bases can deform. This is impossible with TMJ's seamless jacket. TMJs don't foul ported recoil compensators like open-base rounds do, therefore airborne lead is reduced. Each bullet is swage twice to ensure proper diameters and a uniform heel. TMJ bullets are ideal for plinking and casual practice since they are both super-accurate and cost-effective.