What is the difference between TMJ and FMJ?

TMJ stands for total metal jacket ammo, and FMJ stands for full metal jacket ammo. Neither of these two was made to expand on impact. However, their difference lies in their penetration and price range. Since TMJ is considered to be a plated bullet, it has been observed that its penetration into a hard target is not as effective as using an FMJ.

Since the plating is more breakable on the FMJ, it will likely fragment more as compared with the full metal jacket. TMJ is more expensive than FMJ. TMJ is made of brass or copper, and it is usually used indoors to cut the lead content in the air. FMJ's jacket is traditionally made up of solid material such as copper-nickel, brass, or steel alloy. It is also used in gas-operated weapons.