Home | read this | for rent | special orders | on the set | fix it in post | legal issues | faq / contact | tutorials
Deathmonkey Armourers
read this page

Guns 101

Here's some basic information to get you comfortable with the terminology used on the site. If you're not altogether familiar with how firearms work, here's the intro lesson.

The Mechanics

To be accurately called a gun in the sense of being a firearm, an object has to propel a projectile through the air driven by an explosive charge. Typically, the explosive is gunpowder; the projectile is a bullet; and bullet and powder are packaged together in a brass cylinder, called a casing or shell.

This entire package, or cartridge, is then loaded into the gun's chamber. Most guns have a spring-loaded hammer, which can be cocked back and then is released when the trigger is pulled. When the hammer is released, it engages the firing pin, which strikes the back of the cartridge, igniting the compressed gunpowder inside the cartridge and propelling the bullet out through the barrel of the gun and toward its target. Cartridges are typically loaded into a magazine, or clip, which attaches to the gun and feeds the chamber.

Pulling back the hammer to cock and then, separately, pulling the trigger to release the hammer is considered to be a single-action method. Most single-action guns can also be fired double-action, which means that pulling the trigger will both pull back the hammer and then release it, instead of just releasing it. Firing a gun double-action makes the trigger more difficult to pull, because of the energy required to cock the hammer.

Revolvers

A revolver has a cylinder that can hold six or eight cartridges, and when the hammer is cocked the cylinder revolves to bring the next cartridge into firing position. When the trigger is pulled, the hammer releases and triggers the firing pin. When all the cartridges have been spent, the cylinder can be swung out or the gun can be opened to allow the spent casings to be emptied and the gun to be reloaded.

Automatics

A gun is considered automatic when, after being fired, the next cartridge is automatically loaded into the chamber. Holding down the trigger will result in continuous fire until the chamber empties; a semi-automatic gun is one which will chamber a new round after each fire, but will only fire once when the trigger is pulled. Fully automatic guns made after May 19, 1986 are illegal for civilians to purchase in the United States. Newer automatic rifles are permitted only if they have been modified to fire semi-automatically.   Guns made before the cutoff date are, according to Federal law, legal to own -- but state laws vary, and many states (including California) are more restrictive.

Semi-automatic pistols require an initial motion to load the first round into the chamber. Most pistols have a slide action, meaning that the top portion of the gun slides back to allow the first cartridge in the spring-loaded clip to pop up; as the slide returns to its original position, it pushes the cartridge into the chamber.

This motion of pulling the slide back is called racking; the action, or mechanism that loads the cartridge, must be worked like this in any automatic or semi-automatic when it's first loaded. Subsequent rounds will chamber automatically after the first is fired. On rifles without slides, the action is more often referred to as the bolt, and similarly requires being pulled back and released to chamber the first round from the magazine.

When an automatic or semi-automatic is fired, the force of the explosion drives the slide (or bolt) back, allowing the empty casing to fly out and a new one to take its place. If the action is worked manually without the gun being fired, the same thing happens; the cartridge (unfired) will fly out and chamber the next. When the magazine is empty, the action will lock in the back position.

A cocked automatic, with magazine removed, still has one round chambered and the action should be worked to free the cartridge. Many people have died by not realizing that one cartridge remained in the gun after removing the clip.

If the gun is cocked, it can be uncocked by holding the hammer, pulling the trigger to release the tension on the hammer, and then gently lowering the hammer back down so that it doesn't engage the firing pin.

Rifles

Rifles have long barrels that are grooved on the inside in a spiral fashion, causing the bullet to spin and thus travel straight a greater distance before beginning to fall. Long-range bullets, like sniper rounds, are streamlined to travel faster in the air and come packed with a large charge of gunpowder to generate more force and thus fly farther. Many rifles have a bolt action that must be worked back manually after each shot to chamber a new round.

Measurements

The caliber, or size, of a gun or bullet is determined by measuring across the diameter, or bore, of the ammunition. Imperial measurements, such as .22, .357 and .45, approximately refer to fractions of an inch: .357 is just under 3/8 of an inch, for example - although what we call a .357 bullet is actually 0.38 inch for reasons we won't go into. Suffice to say that the caliber can generally be used as a rough measurement of the dimension, but more accurately serves as the unique "name" of a particular cartridge, e.g. .357 Magnum, .30-06 Winchester, etc.

Metric measurements are in millimeters (such as 9mm). Smaller bore rounds, like .22, are used in hunting and target shooting, and are less effective in terms of power than larger bores. There are many stories of the disenchanted attempting suicide with a .22 and ending up with a bullet lodged in their skull and a speech impediment.

Shotguns

Shotguns typically use large cartridges packed with gunpowder and either bullets or shot (many tiny lead pellets). Shot will spread out as it travels and has great destructive power. Double-barreled shotguns typically crack, or open, allowing single cartridges to be placed into the back of the barrel. Double-barreled shotguns have two triggers, one controlling each barrel, and are often used in hunting.

By contrast, single-barreled shotguns more often have the pump action so popular in the movies; many cartridges can be loaded into the bottom of the gun and each pump of the action will eject the spent shell and then chamber a new cartridge. Sawing off the end of the barrel after the pump is illegal for civilians to do in the U.S. because it makes the guns easier to conceal.

Like any other gun, a shotgun's distinct ballistics (firing pin imprint, for example - the "fingerprint" of a gun) can be used to match a casing and a slug to a particular gun - but in the case of buckshot, there is no way to positively match the individual shot pellets to that particular gun. However, the pellets' chemical composition can be matched to other shot (say, from an unfired cartridge).

Shotgun ammunition is counted in "gauge", as in 12 gauge. Gauge is measured as the number of lead spheres of a particular diameter required to make one pound; thus "12 gauge" is a measurement referring to a the diameter of a sphere weighing 1/12 of a pound. Thus, "10 gauge" is a larger physical measurement, "14 gauge" is a smaller diameter, etc.

Other Parts

The butt of a gun refers to the back end; on a shotgun or rifle it's the end of the stock that rests against the shooter's shoulder, and on a pistol it's the bottom of the grip, where the clip is inserted. The muzzle is the very front, the hole in the end of the barrel, where flame and smoke often shoot out as byproducts of the gunpowder explosion.

Cause and Effect

The more powerful the gun, the louder the sound, and the more powerful the kick, or recoil, in the hands of the shooter. Dislocated shoulders are common among shotgun lovers.

A bullet hitting a body will often ricochet off of bone, tearing through muscle and tendons, and may or may not exit the body, depending on how much of its momentum has been transferred to structures in the body - like a billiard ball, the bullet acting as the cue ball will strike whatever's in its way and transfer its energy. Bullets are often made of a soft metal like copper, so that the copper will mash up and not pass right through whatever it hits. Shot bullets, or slugs, can do a lot of damage caroming off bones.

Silencers

Silencers, or suppressors, screw onto the end of a pistol or rifle's barrel (less so revolvers, since the cylinder is open and sound escapes there) and are basically a collection of baffles to capture the energy of the gunshot, releasing it slowly instead of all at once. It's not unheard-of for some to use empty 2-liter plastic bottles as suppressors, attaching them to the gun's barrel and then firing through the bottom of the bottle. A properly suppressed gunshot sounds more like a dry cough than the sharp zip heard in movies.

Machine Guns

Machine guns are those typically considered those that feed their ammunition through the chamber on a belt, often fed by a second person. The spent casings emerge from the other side still attached to the belt. Often machine guns, given their power, are stabilized by being mounted to vehicles or using stands to brace against the ground.

Troupers.jpg
Improper usage of a Glock 9mm

Before you shoot

Nothing is anything without planning. Endeavors as complicated as filmmaking prove this every day. And you want to plan as much as possible before pulling guns - even fake ones - out onto a set.

While it's not our place to suggest that you don't need our services, consider the story of your film and the roles that firearms play in it. We've all seen action movies and cop shows and Westerns where everyone's packing heat and people drop like flies, but also consider the role of the gun in a film like STAND BY ME - more powerful because of its brief screen time. If it was in every scene its effect would be muted.

Also consider your character's reactions to the firearms. This is an issue of context. Of course soldiers and policemen behave a certain way around guns; bank robbers and drug dealers likely behave a different way. The most powerful scenes involving guns are when someone wholly unfamiliar with them - or even afraid of them, as we all probably would be in a real-life violent situation - is abruptly confronted. Carefully gauge your characters' actions and reactions.

English.jpg
JOHNNY ENGLISH doesn't need a gun to feel like a man

We're off our soapbox now. So, on with the firearms! Depending on your budget and the level of realism you're looking for, you have a lot of options. Most of the guns you see in action movies are rubber or resin props, and only a few are functional (for close-ups). This is a service we hope to provide in the future.

What many people think of when they consider movie prop guns are blanks. Blanks are essentially live gunpowder charges, similar to regular bullets except they're not loaded with a projectile. Sometimes blanks can be loaded in real guns (this is occasionally done in the movies) and there are some replica guns that will ONLY fire blanks, and cannot be modified to fire projectiles (our Beretta is one such example).

There are advantages and disadvantages to blanks. On the realism side, they do produce smoke and (sometimes, depending on the gun) a flash; if using a gun with a plugged barrel, typically the casing will eject from an automatic; they produce sound and a "kick" that helps the actors retain the realism of the scene. However - they are VERY loud. Outside of a strictly controlled area you are liable to have cops charge your set. When used in a gun without a plugged barrel, the casings may not eject properly, causing jamming; also, burning gunpowder can travel up to several feet through a clear barrel and cause serious injury (our Beretta has a plugged barrel, and does not have this danger). A plugged barrel will produce a flash at the chamber, not at the muzzle.

Many movies (especially for things like Gatling guns and artillery) will use propane-powered guns, where an igniter inside the assembly will create short bursts of flame to simulate gunfire. Often there is a separate mechanism to throw out shell casings, and the sound is added in post. This requires not only the propane and the gun, but a union pyro technician and a fire safety crew, and is usually reserved for large-scale productions.

"Non-Guns" are electronic devices that look exactly like guns, but have no gunpowder or other high explosive. They are loaded with charges that produce a flash at the barrel when triggered, very quietly and relatively safely. They can be triggered by hand or wired to a board, and can also be wired to synchronize with squibs. The following is not an expert opinion: it seems that while there are a lot of obvious advantages to Non-Guns, for the sticklers among us there is still the question of casing ejection and slide movement; in addition, the flashes produced don't look like gunpowder flashes, and the cost, while fairly reasonable, is prohibitive for someone on a tight budget.

And finally, an important note about realism. While it will only be to your benefit to emphasize accuracy when you're dealing with firearms - since they evoke such strong reactions, and the illusion of realism is one of the tasks of the filmmaker - remember that your job as a filmmaker is to tell your story in the most effective way possible, and sometimes that means fudging on some of the details - a good example is Hollywood's convention of eschewing the actual sound of gunfire with the loud, terrible noise that we're all used to, because it evokes a stronger response.

How you treat your gun on set and in post will accomplish most of the job of convincing your audience that your actor's holding a live firearm. Please continue reading our other pages to learn more.
One.jpg
Soldiers from THE ONE made their guns in arts & crafts



All information supplied is at your own risk. Check with legal authorities for local laws before attempting your shoot.