So here’s a topic we haven’t covered before on AccuracyTech…bullet trace! It’s been referred to as a vapor trail, shock wave, etc. but regardless of what you call it let’s be specific about what we’re seeing. If the conditions are right and your optics are positioned appropriately you can actually witness the passage of the bullet in flight as it moves through the air in front of you. You know how if you take a bottle of water and swirl it real fast you can see a little water tornado in the bottle? If you were somehow able to turn that bottle on its side while that was happening so the small tip of the tornado was facing away from you and the large part of the cone was nearest to you, that’s what it looks like in flight. Like a little vortex turned on it’s side. The neat thing is you can actually track the bullet in flight! Hence the term, bullet trace.
I want to clarify something from the get go, bullet trace is not the same thing as a vapor trail, though the terms are often used interchangeably. A vapor trail is what you see off the tip of a plane’s wing and it looks like a little white cloud. It is possible to see this with a bullet but it’s pretty rare. Bullet trace on the other hand is much easier to see and stumble across. Essentially what you’re looking at is the air being disturbed by the bullet’s supersonic passage en route to the target. The light hits that air differently than the air around it because of the wake created by the bullet and you see the resulting air disturbance. It’s a great indicator of where the bullet is and where it’s going in real time!
Using Bullet Trace
If you can see the cone trail of bullet trace behind a bullet in flight, how can you use that to your advantage? Easy, it’s a poor man’s tracer round! Instead of using a bullet that’s burning in flight to track the arc and destination of bullet’s in flight, you can do it for free with bullet trace! Ideally you want to position yourself behind the person shooting in order to observe this. Try to set up so you can draw a straight line from your spotting scope, through the shooter and his rifle, to the target. This way the bullet should arc up in front of you and back down to the target. You’ll be able to see it drift left and right given the right conditions and enough flight time to observe the drift. Sounds great, but who cares? If you can spot whether you hit or missed, and by how much, what’s the point of looking for bullet trace?
Well, this really comes into play in wetter, more humid, shooting environments. Here in Colorado where it’s very dry it’s easy to kick up dust and dirt with a bullet and observe the impact and how much correction, if any, you need for a second round hit. However if the ground is very wet, like in the springtime after snow melts, or if you live in a more humid part of the country, sometimes seeing any impact signature at all is a real challenge! This is where bullet trace falls into place. If you can observe the trajectory of your shot in flight that gives you some instant feedback as to where it’s going and how accurate your wind call was. Even if there is a tiny impact signature, if you follow the trace in while shooting in a wet environment, you’ve got a better chance of seeing it. Nobody likes hearing, “Miss, no call” after a shot. That’s about worst case scenario, you didn’t hit the target, and nobody knows where the bullet went!
I don’t have much in the way of pictures of this because it’s basically impossible to photograph, you would have to pull stills from a video and even then without seeing the frame before and after noting the small disturbance is difficult. I’ve included a video below and if you watch the lower right hand corner of the screen you’ll see the bullet arc towards the target and hit. There are two shots that show good trace in the video. If you have to watch it again, that’s okay…but if you watch carefully it’s there. I’ll try and do a better video of it for next time! I do suggest viewing full screen, in 1080P full HD, click the cog on the YouTube video and make sure you’re watching in full 1080P. You’re looking for a small disturbance in the air and even the difference between 720P and 1080P makes a difference.
This isn’t anything superific or absolutely essential. Like anything else, it’s a useful tool in the toolbox. If you can get set up to observe your own bullet trace in flight, or that of a buddy, you have a much better and more complete picture of what the bullet is doing in flight. In fact, at the longer distances, you’ll be able to predict a hit or miss before the bullet even arrives at the destination based on the angle. I didn’t have the camera in the best spot for catching this and I’ll try and do another in the future with a more dead on angle of the bullet’s path. Obviously it’s easier to predict what’s going to happen if you’re positioned in line with the shooter. In any case, now that you know what it is, try to position yourself so you can see it and hopefully it will help you in your spotting, or shooting, at the range. As always if you have questions or something to add, please do so in the comments below!