Full Metal Jacket Boat Tail (FMJ-BT) Bullets Explained
As with any full metal jacket, the full metal jacket boat tail has a bullet either fully or mostly encased in copper or another hard metal or material. The boat tail type is commonly used for shooting matches, competition or occasionally, hunting use. The way these are designed is with a tapered rear of the bullet and when viewed from the side, they roughly resemble the way a boat is shaped. These rounds are favorites of reloaders because they tend to be easier to assemble without denting, nicking or scratching the bullet surface. Any tiny imperfection can lead to unwanted bullet performance or even cause issues with the casing. With boat tails, the tapered end can lead to more stable flight and a reduced ballistic coefficient, leading to improved accuracy at longer ranges.
When the bullet is fully encased it can be called a TMJ or total metal jacket bullet but these are commonly only encased on all sides but the rear. The reason for the casing is two-fold. It can limit the amount of lead spread in the air when firing and can add penetration. Full metal jacket boat tails tend to be fully encased to limit lead issues even more.
As mentioned above the two most identifiable advantages are the clean aspects of range shooting along with the accuracy and penetration of this bullet type. The airborne lead issue has raised various concerns over the years and is something to think about if you shoot a lot because it can be detrimental to your health. Having a fully encased bullet or a specially designed non-toxic type is the easiest solution here.
Accuracy is key in shooting matches and during practice or training so anything that helps ballistically is a benefit. Shooter forums seem to be 50/50 on boat tails with some praising them to the extreme while others don’t notice a lot of difference compared to other match ammo or premium types. The key factor will be with you and your gun.
Another advantage is for reloaders. The way the bullet is shaped makes it easier than normal to attach to the casing so they are very popular in this regard.
There aren’t a lot of true disadvantages to this bullet type unless you’re using them for something other than their primary use. Depending on the manufacturer this could be competitive shooting, long range practice or even hunting. The one thing a lot of FMJ bullets suffer from is penetration. These bullets can hit a target, go straight through and keep on going. This is because unless they were designed to tumble or fragment, they remain pretty much intact on impact. This will depend on the target material of course. Typically you won’t be using these bullets for home defense unless the zombie apocalypse happens to occur.
Some areas don’t allow the use of any FMJ bullets, even boat tails so make sure you know what’s allowed on the range you’re going to, the hunting area or other public land so you don’t get in trouble once you start shooting.
Written by Sam Jacobs