Advanced Ballistic Concepts

Multiple Impact Bullets



Multiple Impact Bullets

Bullet technology for self defense has gotten a bit of tunnel vision as of late. Manufacturers have been competing over penetration/non over-penetration, expansion, and weight retention quite heavily these days. While what the bullet does when entering the body of an attacker is important to a point, there is a variable that all these fancy bullets doesn't take into consideration. Under the immense stress of a lightning fast confrontation in a self defense scenario or threat encounter, you are likely to miss your target all together. While I'd love to quote a legitimate statistic on how many bullets fired in self defense scenarios hit versus miss, I would wager the number is less than 50%. Some self defense training courses offer the statistic that Law Enforcement shootings at 15 feet or less result in only a 10% hit rate. While a percentile of 90% shots missed seems abnormal, many who have actually been in the heat of the moment can attest to the difficulty if not trained, mentally prepared, and 100% on their game.

Multiple Impact Bullets

For ages, the shotgun was touted as the king of home defense because of the spread of birdshot or buckshot and the disregard for aiming properly. While half-true, the spread of shot can be irregular and inefficient, and requires travel distance after leaving the muzzle to adequately expand. What if there was a way to apply the concept of multiple projectiles in a handgun cartridge, giving the shooter a round with consistent increased hit probability, while retaining enough energy and terminal ballistics to stop the threat? If the projectiles can be given a controlled spread, misses off the body due to incorrect point of aim can still retain a chance of striking a hit.

Multiple Impact Bullets

A Colorado based company called Advanced Ballistic Concepts, LLC has designed a bullet that strives for the aforementioned goal. Multiple Impact Bullets or Mi Bullets™ are designed to take advantage of the spinning forces generated by a rifled barrel. When an Mi Bullet leaves a rifled barrel, the forces cause a rapid release of the bullet's tethered segments, expanding to a desirable radius in a much shorter distance than buckshot leaving a shotgun barrel. The inspiration for this concept is one I can relate to. Co-Founder Todd Kuchman was out camping and encountered a grouse, with only a rifle and pistol sidearm. Wanting to harvest the grouse for a savory campfire meal, he thought about the astounding feet of marksmanship needed for a perfect headshot, resulting in no damaged meat and a clean humane kill. While to story doesn't detail whether fowl was on the dinner menu that night, the inventor began brainstorming how a more forgiving projectile could be invented. After a home invasion experience and subsequently diving into the world of self defense courses, the concept for the Mi Bullet ™ was developed into three primary variations: non-lethal (Mi3 Stinger), semi-lethal (Mi3 Stunner), and fully lethal (Mi3 Stopper).

Multiple Impact Bullets

The Mi Bullet ™ consists of interlocking MI4™ segments assembled into a single projectile, that when fired and traveling down bore of the rifled barrel, begins to spin. As the projectile assembly leaves the muzzle of the firearm, the spinning forces imparted by the rifling causes the interlocked portions of the projectile to simultaneously move rapidly outward (Accelerated Radial Spread™) away from their original center of rotation with a 120° spacing from one another, still spinning to achieve stabilization along the original trajectory. How the ammunition differs between Stinger, Stunner, and Stopper (lethal, semi-lethal and non-lethal) comes down to the velocity and density of projectile materials (lead vs plastic, rubber, etc.) The 45 acp fully lethal Mi Bullet™ consists of a single buckshot weighing 31.5 grains, surrounded by three segments ranging between 36.5 - 37.5 grains, collectively forming an approximate 142 grain projectile. The 12 gauge fully lethal Mi Bullet™ slug consists of a 75.5 grain bullet-shaped core thats surrounded by three segments weighing between 205 and 210 grains each, adding up to a whopping yet approximate 700 grains slug. As a reloader, the weights of each individual part interest me, as does the inconsistency of the segment weights.

Multiple Impact Bullets

The key to the controlled separation of the segments is a multi-staged tether/brake™ system that balance the expanding radial forces with the centrifugal force to gyroscopically stabilize the orbiting segments around their original center of rotation as if it had remained a solid slug. There's alot of physics language on the website if you are interested in the science behind the concept. For my fellow laymen, the bullet has a core and connected segments that expand into a Y shape rapidly out of the barrel, giving you a projectile that forgives close misses. It's important to know that the radial spread doesn't stay constant at 14", at it travels it will pulsate at the tethered segments expand and contract from their center axis. While still possible to miss enough for all the parts to miss their target, the tethered fragments do grant you a better chance of a hit. In a life or death confrontation, and glancing flesh-wound of the abdomen can still carry a chance of striking near center mass with a segment and stopping the threat.

Multiple Impact Bullets

In my range test, I found the 45 acp full-lethal round to have a full spread at around 10 to 15 yards, my initial shot at 15-20 feet didn't reach the advertised radial spread. The core of the 45 bullet just a round buckshot pellet, and doesn't hold much accuracy despite the segments acting like a sabot. Interestingly enough another shot had struck the neck, and a segment had wrapped around to the back of the head and embedded into the spine, like a bolo wrapping around prey.

Multiple Impact Bullets

Giving the 12 gauge full lethal shells a turn, The segments spread well at mid range, wide enough to span the face of Bobby Bluebeard completely. Mr. Pink however was not so lucky, as the 12ga core glanced his left temple but a segment nailed the forehead and blew out the back (foam not an accurate analog for the human head). This demonstrates the goal of the Mi concept: increase your odds and turn close misses into direct hits.

Multiple Impact Bullets

 As for the legality of shooting and killing someone with a non-lethal or semi-lethal round, I'm not touching that with a ten foot pole. Multiple Impact does color the packaging for each (Green for non lethal-stinger, Orange for semi lethal-stunner, Red for full lethal-stopper). If I hadn't already known that differentiation I would have had a difficult time because the ammunition itself isn't marked on headstamp or hull, and the packaging is so cluttered with marketing buzzwords and trademarks that its a tad overwhelming, at least in the eyes of a professional graphic designer.

Multiple Impact Bullets

I would have loved go for a hike in the woods and report back with a harvested grouse or rabbit using my 1911 and the 45 acp Mi Bullet ™ but there were none to be found on that day as luck would have it. Obviously these rounds are specifically designed for human size targets, as the spread can be between 10" and 14" as the range that grouse or rabbits typically afford me before their wits finally kick in and they scurry off. Perhaps a 'small game load' pistol round could be in the works later on down the road with a shorter radial spread and perhaps more than 3 segments, in different calibers as well including revolver cartridges. One can only dream! For two legged threats, the concept behind the Multiple Impact Bullet is very interesting and innovative, but it won't replace my favorite hollowpoints just yet. I look forward to seeing the execution and marketing strengthen over time.

Firearms Insider Reviews – 8 Key Points

Claim to Fame:  One-of-a-kind bullet technology makes it possible to achieve an unprecedented combination of stopping power and high hit probability

Target Market:  Self Defense, Home Defense, Security/LEO

FNBs (Features & Benefits of this product):

  • High hit probability
  • 99% firearm capability
  • Full lethal, Semi Lethal, or Non Lethal
  • Quicken response time
  • Deep-impact™ Technology

What other aesthetic options or finishes are available?: N/A

What others are saying?:

"As it turns out my testing at different ranges doesn’t accurately tell the whole story of the bullets expansion. As the bullet flies downrange the diameter is constantly increasing and decreasing in size, or pulsing. At its smallest size the dispersion might be 5″ and at its largest it will be limited by the length of its tethers, which is 14″.

I did notice at 7 and even 15 yards the point of impact was pretty much where I had aimed. At 25 yards the projectiles had veered off course and struck left of center, but still scored a solid hit on the target.

I pulled a bullet apart to see what made the rounds tick and found a simple coil of string tethering three copper/zinc alloy projectiles together. Each of the bullet fragments weighed right at 40 grains with a variance of a grain or two between them. This variance is likely what contributed to the fired round drifting from point of aim at distances greater than 15 yards. I wasn’t able to fire the rounds over a chronograph to measure bullet velocity as I was concerned I might hit the device. As of this writing the manufacturer hasn’t published velocity data on the bullets.

As of right now it’s too early for me to pass judgement on this unique new defensive round. What I can say is that the concept is innovative and I personally find it to be interesting. Will it replace my 147gr 9mm Gold Dots anytime soon?  No, not at the moment, but stick around as I put this new ammo through its paces. Who knows, maybe it will knock my socks off." The Bangswitch - Military Arms Channel Blog

Price point:

I need it now! Availability:

Our Rating:


  • Even out of a 18.5" smoothbore shotgun barrel, the semi-lethal and full-lethal segments spread decently at short range, a much better spread than with regular buckshot.
  • No failures or malfunctions, both rounds cycled test guns (gas operated Mossberg 930 - even lowbrass!, and Ruger SR1911)


  • Shotgun slugs protrude past the shell, reducing overall capacity in some magazine tubes by 1 shell - did not test in box magazines
  • No data yet on safety with suppressor use
  • The Mi Bullet suffers from over-marketing - the packaging has so much trademarked buzzwords its overwhelming
  • Price per bullet is considerably higher than other tried and tested defensive ammunition.

Score: 7.0 Good



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