The NPA proprietary HELO family of products was originally designed for law enforcement and specifically to pass and exceed all FBI performance protocols. Unlike bonded jacketed bullets the HELO is formed from a solid piece of high grade virgin copper and then a proprietary cavity is formed , the copper bullet is further processed with a proprietary manufacturing method to allow the projectile to achieve maximum penetration and expansion while retaining 100% of its grain weight through ballistic gel. Bonded lead jacketed bullets are much more ductile than copper and deform even when dropped by accident which can cause the bullet to fail to open but the HELO Defense is made of solid copper that will not deform when dropped or push back when chambered multiple times.
Also, solid copper cannot separate from a jacket because there is no jacket which is why the bullet will consistently penetrate and expand even when shot through heaving clothing. Finally, the HELO Defense does not break apart into smaller pieces upon contact with soft tissue which immediately loose energy and weight like many machined copper hollow points on the market today which would score low in the FBI Protocol tests.