Frequently Asked Questions

What Is SUBMASS™ (Weight)

SUBMASS™ is classified as a new weight category in bullet technology. It is the lightest personal defense and Range/Training ammunition on the market, even lighter than frangible ammunition. For example, the standard bullet weight for 9mm Personal Defense ammunition is 124grains. The SIM-X 9mm DEFENSECORE™ 45gr bullet is 2.75 times lighter. The standard weight for 45 ACP ball ammunition is 230gr. The SIM-X RANGECORE™ 80gr is 2.875 times lighter.

What Is SUBMASS™ Technology?

SIM-X Patented SUBMASS™ Technology is both why and how, lead free, ultra-light-weight ammunition reliably functions in unmodified, off-the-shelf, firearms, and at velocities two times that of lead ammunition. Additional benefits include customized, scenario-dependent, ballistic outcomes with nearly 100% penetration control.

What Is Hyper Velocity?

SIM-X ammunition produces “Rifle Velocities in a Handgun.” Simply put, it is twice as fast as comparable lead ammunition. The average velocity of lead 9mm Personal Defense or Training/Range ammunition is 1100 feet per second. The velocity of 9mm DEFENSECORE™ is 2250+ feet per second. The average velocity of lead 45 ACP Personal Defense or Training/Range ammunition is 890 feet per second. The velocity of 45 ACP DEFENSECORE™ is 1825+ feet per second.

What Is Performance Recoil?

Utilizing proprietary SUBMASS™ projectiles, SIM-X ammunition rewards the shooter with the lightest recoil compared to similar use rounds on the market. Utilizing a Ransom Rest to eliminate shooter introduced variances, SIM-X 9mm DEFENSECORE™ produces, on average, 40% lighter recoil than 124gr lead-core Personal Defense ammunition. SIM-X 45ACP DEFENSECORE™ ammunition produces, on average, 50% less recoil than 230gr lead-core Personal Defense ammunition. This results in better firearm management, important for all shooters. Less recoil equals less shooter fatigue and faster more accurate follow-up shots. Simply put, shooters perform better using SIM-X ammunition. Performance recoil needs to be experienced and enjoyed.

Is Your Ammunition Lead Free?

Our patented bullet technology is 100% lead free. The anatomy of the projectile/bullet consists of a standard copper alloy jacket with a non-toxic synthetic polymer core. The case, powder and primers are all industry standard, off-the-shelf, components.

What Does it Cost?

The SIM-X DEFENSECORE™ product line is comparably priced with other premium, Personal Defense ammunition. The SIM-X RANGECORE™ product line is the most cost-effective, lead free ammunition currently on the market—up to 30% cheaper than frangible ammunition. If you are looking for a premium, lead free bullet with performance recoil to utilize for training at the range, the nominal additional cost is well worth it for the superior performance. The shooter is getting a premium training round at or near ball ammo prices.


Achieving (near) absolute penetration control can now be achieved utilizing SIM-X SMART BULLET TECHNOLOGY. This holds true regardless of projectile velocity. The SIM-X DEFENSECORE™ patented design for the 9mm, 40 S&W, and 45 ACP pistol calibers produce the highest transfer of energy within the target while maintaining nearly 100% penetration control. When shooting through materials like clothing, conventional lead-core bullets often fail to expand due to material clogging the hollow cavity in the nose of the bullet. DEFENSECORE™ bullets penetrate any type of clothing or solid material while still expanding. How is this achieved? By expanding from the base to the nose, a first in bullet technology. The result is the most consistent expansion and energy transfer of any bullet currently on the market.

What Is Barrel Burnout?

Every barrel has a shot cycle life, some lasting longer than others. In the world of lead, higher velocities typically equal higher pressures and increased wear on the barrel and chamber. This changes muzzle velocities (MV) throughout the life of the barrel. If the projectile/bullet was manufactured using lead and loaded to match the velocities of a SIM-X round, it would require pressures that would be two to three times greater than the barrel is designed to withstand. Pressures this high could result in a catastrophic barrel failure. All SIM-X products produce pressures that are within SAMMI specs and having a malleable core allows the projectile/bullet to pass through the barrel with greater ease with what we call “soft friction.”

What Is the Difference Between Clear Ballistic and FBI Gel Block?

Clear ballistic gel is an excellent marketing medium to demonstrate lead ammunition terminal ballistics. But the true standard for testing and demonstrating real world ballistics is the FBI gel block. SIM-X ammunition—specifically our DEFENSECORE™ products—do not react the same in clear ballistic gel as they do in a true FBI gel block. Example: the 45 ACP DEFENSECORE™ will fragment when shot into clear ballistic gel but expands and remains intact when fired into an FBI gel block. To demonstrate true terminal ballistic performance, SIM-X only uses gel blocks made to exact FBI specifications.