Muzzle flash: look where I am!

<< More bang, less light: Explosions in film and TV (Part 2)

Firearm fails: Pushing the envelope of pistol performance (Part 3) >>

Welcome back to my blog, whether you’re a new or returning reader. This week we’re wrapping up our series on Hollywood explosions with a focus on gunfire, specifically muzzle¹ flash. Although a gunshot is a very different type of explosion to a bomb (more on this below), it still:

• Makes a bang…
• …and a flash…
• …and said flash is wildly exaggerated by filmmakers…
• …for reasons both good and bad.

So we’ll talk about it below, with the same lens of comparing the reality with various examples from film and TV, and discussing why certain artistic choices are made.

As always, please like and subscribe if you want to see more, and share with like-minded pendants. Thanks, as always, for your continued support and engagement!

If you enjoy this blog and want to support it, please consider a donation. Keeping this blog going doesn’t cost much, but it isn’t free either, so any help would be very much appreciated👍

Thermodynamics and tactics: minimising muzzle flash

Let’s quickly recap on the “energy in” and “energy out” problem for ammunition designers:

The output we want in firearm design is similar to that from an explosive: high pressure gases. The difference is that in a gun we are using these gases to accelerate a bullet rather than using the gases to accelerate lethal fragments. The other big difference is that we want to release the energy in the propellant far more slowly than we do with an explosive: several hundred or even thousands of times slower. The reaction is slower, a “deflagration” rather than a detonation:

Although the chemical reaction is different, the approach of filmmakers is the same as with high explosives. They emphasise the bright flash of gunshots, with fireballs erupting from gun barrels:

Real gunfire, by contrast, looks like this:

It’s not that there’s no muzzle flash with real guns: far from it. But it’s much dimmer than depicted on screen, and barely perceptible in daylight. Muzzle flash is a real phenomenon and something of a problem for weapon and ammunition designers. It actually consists of several distinct components, not that you asked². But weapons and ammunition are designed to minimise this muzzle flash, for two important reasons.

The first is to preserve the shooter’s night vision when firing in darkness. Having spent hours getting your eyes to adjust to the darkness for maximum vision, the last thing you need is a bright flash blinding you for the next hour, right when you need your night vision the most. The second reason, which is pretty obvious, is to avoid showing the enemy where you are.

We want to minimise muzzle flash, therefore, and we have two ways of doing this: additives to the propellant and muzzle flash hider/eliminators. And they work, as you can see from the real examples above. The movies exaggerate it for one of the same reasons we try to minimise it in real life, which is to draw the viewer’s attention to the firer. But how do they do this?

The complications of blank firing

Just like with the explosions discussed in the last two posts, there are two ways that moviemakers can achieve the bright muzzle flashes which viewers expect. One is digital, which we won’t dwell on too much here, but is obviously very cost-effective and improving with technology. You can do an image search on Google for muzzle flash effect and see a selection of the kinds of templates a filmmaker can download to put into their films.

The other, non-digital, way that filmmakers get those fiery flashes is with a special type of blank ammunition that has extra propellant or other modifications to enhance the flash effect. There are complexities to firing blank ammunition, however, whether in film and TV or in tactical training. Safety is obviously a big consideration, because blanks can still cause serious injury with high-pressure gas and small fragments, as played for dark humour in In Bruges, with some sophisticated name-calling for good effect:

Another problem with blanks in automatic weapons³ is that they don’t work properly without a special attachment plugging into the muzzle. This traps gas inside the weapon, just like a bullet would, and it also makes the weapon safer by absorbing the small brass fragments and taking some energy from the propellant gases. In the military, these attachments are big, brightly coloured (for safety, so you can tell if they’re missing) and attach to the end of the barrel. Some are even designed to stop live rounds accidentally loaded and fired from the weapon. Theatrical weapons need to be more realistic-looking, so they put these attachments or “restrictors” inside the barrel. This means that you still get the “star” pattern flash as the propellant gases exit laterally through the gaps in the flash hider. It seems to me that many of these sequences, and definitely most of the digital muzzle flash templates, exaggerate this effect. So the flash hider contributes to the biggest muzzle flash effect in film and TV:

There’s one more aspect of gunfire to discuss before we finish, and, this time, for once, Hollywood screenwriters and directors hold back on a visual effect.

“Follow my tracer, but not back here!”

Tracer ammunition has surprisingly little impact in film and TV. In fact, it’s the one area where Hollywood shows restraint. By way of explainer, if you’re not aware, a tracer round leaves a visible light trail behind it as it travels through the air. This is useful for 1) Seeing where your rounds are landing and 2) Pointing out to others where you’re shooting (let’s say you want to show your section where to fire: “Follow my tracer,” is the order).

It’s achieved with a little pyrotechnic charge in the base of the bullet:

Tracer is normally loaded in ammunition belts for machine guns, and sometimes in magazines for rifles, in a set ratio, e.g. three ball rounds to each tracer round:

This results in a strange night-time effect where you’ll see intermittent streaks of rounds through the air, but hear a much more rapid rat-tat-tat of gunfire. With heavy fire, this can be extremely impressive, as in this Saudi Army video. You also get a great insight into just how far and how fast bullets ricochet off their targets, even off water. You can even make heartfelt messages in the sky to a loved one, provided you don’t care about where the bullets land (seriously, this is a problem which kills and injures people regularly):

Now tracer fire looks so undeniably cool in real life that it’s something of a surprise that filmmakers don’t make more use of it. Except it’s no surprise at all, when you think about the practical safety aspects of filming:

You could, of course, add a tracer effect digitally in post-production, but I think filmmakers have two good reasons for not doing this. Firstly, there’s the previously-mentioned Coconut Effect. Audiences don’t expect to see tracer rounds flying through the air, so they would think it’s unrealistic. Secondly, and maybe more cynically, showing the trajectory of rounds on screen would further highlight just how bad some of the shooting is, particularly by baddies. As it is, they just need to show the end result, i.e. sparks⁴ flying close to the hero/heroine’s heels. One example I can think of that does show tracer, though, is the opening scene from Saving Private Ryan:

Here you can see a yellow streak every couple of rounds: that’s just what tracer looks like. If anything, it would look even more prominent in dull dawn conditions. A commentator asked me last week what a “good” scene was regarding explosions, and I think this whole scene is as good an example as you’ll get. Bangs are loud, fragments and sand fly through the air, and there’s none of the blast incendiary ornamentation we usually see with explosions. That, plus the realistic tracer fire.

In fact, this scene works on so many levels besides the weapon effects⁵: the horror, the confusion, the helplessness, the physical discomfort. Sometimes filmmakers get it right, and even a cynic like me is happy (well, not happy—it’s a pretty horrific scene—but satisfied with how they put it together).

Conclusion: Art trumps realism, and I’m okay with that

You read that right: for once, I’m not going to roll my eyes at Hollywood and whine about their depiction of muzzle flash effects. I’m actually okay with it. I’m zen. This is just a necessary part of on-screen storytelling. It makes shootout scenes more compelling because, let’s be honest (and you’ve seen the examples above), real gunfire does not look great. Sure, it sounds the part and feels the part, but it doesn’t look the part. It helps us to keep track of who’s doing what to whom. For the same reason, filmmakers (as far as I’ve ever seen) never show a lag between the sight and sound of a distant explosion, or someone shooting a gun, despite these phenomena being part and parcel of military experience.

In fact, come to think of it, since most people’s interactions with weapons and explosions are through the movies, can we really say that the “reality” I’m talking about in these posts is more valid for your average viewer than the tropes and clichés of filmmaking? Why shouldn’t the abstraction, the art form differ from the source text, and yet remain just as valid?

Before we get too carried away, however, let’s draw a line between a cheesy muzzle flash and a billowing, fiery blast incendiary. I propose we bring out the Unreal-O-Meter:

As we can see, there are different levels of unrealism and silliness. Muzzle flash exaggeration falls on the more benign end, whereas I have less sympathy for the ragdoll physics of Hollywood explosions which I discussed last week.

As with many of these examples I write about, I think the pity is in the opportunity lost to show something really interesting on screen. We’ve all seen the same (wrong) explosion and gunfire tropes for decades now, so much so that they’ve gained their own momentum. Films that do break down these tropes are all the better for it, e.g. Saving Private Ryan, as mentioned above, or In Bruges, which constantly seems to crop up in my examples.

So that’s it: to wrap up our three-parter on explosions and gunfire, what do we come away with?

• Real explosions look way less cool but are way more dangerous than Hollywood explosions
• Explosions need to obey the laws of physics: big explosions need lots of explosives, and timescales don’t magically change when you go into slow motion
• Sometimes, however, artistic licence is merited, such as with bright muzzle flashes and the lack of tracers zipping through the air

I hope you’ve enjoyed this series. If you want to see more on this topic, these two Insider videos are a great watch which I came across while writing this article. And, of course, let me know if you’d like to see more in this vein, or something completely different.

Thanks, as always, for reading and for your support, and please remember to Like and subscribe if you haven’t already!

Featured image: The Matrix, Warner Bros. (1999)

1. The front of a gun, where the bullet emerges. ↩︎
2. Oh, you did ask? Right. There’s 1) Pre-flash (muzzle glow), which is caused by hot gases leaking past the projectile and escaping before it emerges (as the name suggests); 2) Primary flash, which consists of propellant solids or gases which are still burning after the bullet exits. These are a bigger problem with shorter barrels, e.g. carbines (think M4); 3) Intermediate flash, which is the air around the muzzle getting heated by the emerging shock wave of the supersonic bullet; and 4) Secondary flash, which is when the hot gases emerge into oxygen-rich air and combust (for a second time, hence the name). This is the brightest aspect of flash. ↩︎
3. Technically only in gas-operated weapons, e.g. most automatic rifles. To massively simplify, in a gas-operated weapon, the high-pressure propellant gases are trapped behind the bullet as it travels down the barrel. A portion of these gases are tapped and directed backward to recoil the weapon’s actions, eject the round and cycle a new one. With a blank round, there’s no bullet acting as a “plug” in the barrel, so the pressure isn’t high enough to cycle the actions. ↩︎
4. Also unrealistic, but a topic (perhaps) for another day. ↩︎
5. And I know, the bullets killing troops underwater is unrealistic, and has been debunked by Mythbusters. So let’s put that aside. ↩︎