Total Metal Jacket Bullets Explained
Total metal jacket bullets, often referred to simply as "TMJ", are one of the most widely used bullet type at indoor ranges and among competitive shooters. The reason for this is a simple one but important: The normal full metal jacket or FMJ bullet has a small amount of exposed lead at the base of the bullet while the TMJ does not. The TMJ surrounds the otherwise exposed lead area with copper. Using TMJ bullets, along with other steps to minimize lead exposure can make you a healthier shooter.
Technically, a total metal jacket is a full metal jacket so there can be a little confusion among people new to shooting or hunting. In many situations, these terms are interchangeable and a quick glance at a cartridge to see if lead is exposed or not will tell you what they are. The FMJ will have visible lead at the base of the bullet while the TMJ will not.
TMJ vs FMJ Shooting Properties
Both of these types of ammunition are almost identical when it comes to accuracy and velocity. The TMJ round is suitable for target shooting as is the FMJ. When it comes to hunting, the TMJ is not always the best choice as it will not expand as well as other bullets, like the Hollow Point. However, when it comes to hunting large game that requires deep penetration, the TMJ like the FMJ could be the choice.
TMJ and Lead Safety
In an environment where thousands of rounds are fired rapidly among multiple shooters, all the lead particulates floating around create an undesirable amount of potentially harmful air pollution. Over time, this lead accumulates on the ground as well so if you think about how much you shoot in an indoor range for example; it’s easy to see the potential for adverse lead problems eventually. Outdoors, the air disperses the particles enough that it’s rarely an issue.
Some indoor ranges go a step farther and only carry particular types of TMJ ammunition. Some brands, such as the Speer Lawman and Blazer, by CCI use the TMJ bullet. This, along with lead abatement systems in indoor ranges make indoor shooting cleaner and safer than ever.
If you have genuine lead concerns or shoot indoors regularly, the TMJ is probably the better option. Cases of health issues arising from FMJ ammunition are rare, so there is a bit of debate about how much FMJ use can harm you when shooting indoors.
So is lead safety the primary reason TMJ’s are used? Well, the short answer is probably yes, but depending on sites you visit or ranges you use, everyone will have their own, often very strong, opinion about it and this is why many ranges will be very specific about the bullet and casing you use.
If you’re only shooting a little or only during hunting season, there’s no real need to select a lead-free cartridge because you aren’t expelling enough for it to really matter at all. Use your personal preference when selecting your ammo type and you'll be fine. If you decide to hit the range hard, consider the TMJs and check with the range rules.