TMJ Ammo vs. FMJ Ammo

Difference between TMJ Ammo and FMJ Ammo

Total metal jacket (TMJ) ammo and Full Metal Jacket (FMJ) ammo only have a thin difference between them. Even the most loyal and ardent fans are unaware of this difference. This is said that only a pure expert on weapons can spot this difference between these two. Have a look.


Total Metal Jacket covers the lead core of the bullet fully. Made of brass or copper, the TMJ is used indoors to reduce the lead content. A low-cost option to create jacketed bullets, the use of TMJ bullets is mostly limited to indoor shooting ranges.


Full Metal Jacket is ammunition to form a base core around bullets. It’s made of solid materials/metals/alloys like copper-nickel, brass or steel alloy. Due to the lead deposition, FMJ is used mostly in gas operated weapons.

The Difference

The difference between FMJ and TMJ lies in their price range and penetration capability. TMJ is plated ammo and its penetration with a hard target is not as efficient as the penetration of soft plated FMJ. The TMJ is costly as well. The FMJ’s plated metal is fragile and fragment more. Due to the TMJ’s thin plating, the bullets tend to feel limited pressurize in high velocities.  They are safer than FMJ as well because the amount of generated lead content in air is less. However, the experts state that when it comes to shooting, it will be same in shooting or practicing.


  • BlueOx86

    First you said TMJ is a low-cost jacketed bullet, then you said the TMJ is costly… which is it? Also you said that FMJ’s penetrate better, yet are more fragile then TMJ… A fragile bullet will always penetrate less than a more durable one – of the same caliber and weight – that stays in one piece… Thanks for the useless contradicting information.

    • BlueOx86

      Oh yea, and “Full Metal Jacket is ammunition to form a base core around bullets.” Not only does the grammar in that sentence makes no sense, but how do you put a core AROUND something? A core by definition is the center of an object. How can the center of an object form around itself? Just remove this entire page, there is already enough mis-information on the internet.