There is a lot of misinformation about tracer rounds on the web.  Many articles talk about how tracers are corrosive, that they cause barrels to rust, that they start fires or that you can only see them at night or at dusk.  While some of these claims may be true in some tracer rounds, they definitely are not true about all tracers.  

There are two variables that are important when it comes to tracers. One is the size of the tracer round and the other is the placement of the tracer chemicals.  Tracer rounds vary in size from Piney Mountain 22LR tracers to 50 BMG tracers, and the size does make a difference on its ability to start fires.  The 22LR tracers are relatively small and only burn for about 150 meters, as opposed to 50 BMG tracers which can burn out to 1000 meters.  The mass of the tracer chemicals alone creates more opportunity for a fire to start.  

Additionally, the placement of the tracer chemicals is important.  The first possibility is that the tracer chemicals are placed on the back of the bullet using only the copper jacket to contain the tracer chemicals.  A great example of this is Russian made 7.62 x 39 green tracer rounds.  These tracer rounds are corrosive and have a high probability of starting a fire due to their location on the round and that the tracer chemicals make contact with the barrel. This is also why the tracer chemicals can be visibly seen separating from the bullet on impact and sent flying in the air. The second option is for the tracer chemicals to be placed in a cup that is created in the core of the bullet when it is cast.  This type of tracer can be non corrosive depending on size.  The third option is for the tracer chemicals to be placed in a hollowed out projectile which prevents contact with the barrel and reduces the chance of a tracer round starting a fire.  This is the case with Piney Mountain’s 22LR tracers.  These tracer projectiles are hollowed out with the tracer chemicals inside the projectile making them non-corrosive and also not likely to start fires.  Combine this with the fact that Piney Mountain 22LR tracers are the most inexpensive tracers on the market and it’s a no-brainer if you want to have fun with tracers.  

Ryan, Exotic Firearms LLC