This is a great piece written by Matt Pickering who answered this question on a website called Quora.
In no particular order…
- You don’t cock striker fired pistols. “Glock Cocking” is a sign of poor gun knowledge.
- Bullets, pistol and rifle alike, will pass through car bodies from one side to the other. Thin metal, steel or aluminum, is not hard cover.
- Slides lock open on the last round on most pistols.
- People are not thrown backwards by incoming gunfire.
- Bullets do not ignite gasoline, propane or any other type of flammable liquid. Shooting barrels of such material stored conveniently where the antagonists can hide behind is right out. As are exploding gas tanks in cars by being shot.
- There is no database of registered guns or gun licensees to access.
- Outside of places like MA, NJ, New York City and Illinois there is no such thing as “registered guns” or “licensed owners”. If you’re a writer from one of these places, get out to the rest of America and find out how gun ownership actually is. Saying one has a legal registered gun and is properly licensed is stereotype writing and not reflective of reality.
- Full auto firearms are not common. There are no black market sellers selling a variety of military hardware for the person with the right amount of money to acquire. Full auto is so rare that only 3 crimes have been committed with legally owned machine guns in the past 80+ years and only one crime of note, the North Hollywood Shootout in the late 1990s, was done with illegally modified guns to make them fire full auto. Yes, it is that rare. Don’t portray machine guns as common or readily available. They are not.
- Suppressors do not make a “Pfft” sound on anything that is centerfire, pistol or rifle.
- Know the difference between rimfire and centerfire.
- Know what “high powered” means in firearms. Hint: It is not an AR-15 or an AK-47/74 type rifle.
- There is no such thing as a “sniper rifle”. Snipers perform a role. It is not a weapon type. So-called “sniper rifles” are just accurate off-the-shelf modified hunting rifles. The same rifle carried by a sniper is used to hunt deer and can be acquired in the exact same military configuration if one wants to spend the money.
- People are not incapacitated immediately by most gun shots if not hit in the head or central nervous system. If shot by a pistol a person can remain functional for several minutes even if mortally wounded in a vital area. If shot by a high powered rifle a person can be dropped in a single shot. Remember, 80% of people shot by a handgun survive. Learn about terminal ballistics as it does matter.
- There is no body armor that can stop anything more powerful than .30–06 that you don’t sit in and drive. .338 Lapua or .50BMG will go through any worn body armor like it didn’t exist.
- Body armor is heavy. Even soft armor worn under clothing weighs several pounds. Hard armor designed to stop rifle rounds can weigh 20 to 30 pounds easily depending on plate composition and coverage.
- There is no such thing as “armor piercing ammunition” that is designed to penetrate soft police body armor. Any centerfire rifle with sufficient energy can do it.
- Guns are fucking loud! As in “you’ll be shouting afterwards with ears ringing” loud if you discharge any gun in an enclosed space. If Hollywood played gun shots at their actual noise levels in a theater they’d both deafen the audience and blow out their speakers in the process.
- Magazines and clips are different. While a small detail, knowing the difference and using the correct terms will raise your respect level by those in-the-know if you are writing anything where guns are a central part of the narrative. If you can’t understand what is meant by “The soldier withdrew a stripper clip quickly from her pouch, jammed it into the guide, shoved the rounds into the magazine and desperately resumed fire against the charging mass of humanity.”, you need to do more research.
- There are no such things as ice bullets, poison tipped bullets, mercury bullets, guided or exploding ammunition (Note: Guided ammunition prototypes have been built, purely experimental, nothing in service and exploding ammunition is likewise limited. Not something you can buy or make. The reference is to general availability. ).
- Hollowpoints are not designed to penetrate body armor. Nor are they designed to “explode in the body”.
- Teflon coating does not make a bullet able to penetrate body armor.
- Plastic guns with no metal in them that can be concealed, made undetectable and fire regular centerfire pistol or rifle rounds do not exist. The only “plastic gun” that can shoot anything is the 3D printed Liberator and that only shoots a measely .22LR and is more likely to explode after a few rounds.
- An unskilled person cannot get behind a random rifle and make a headshot on a person from several hundred yards away like Call of Duty or Fortnite. Not unless the rifle was configured for that exact range by the person who owned the rifle beforehand, left it behind conveniently for the shooter and there was no wind. Then they might scare the wall next to the person they were firing at. If you want to portray long range shooting, go do some long range shooting (200 yards/meters+) to see how hard it actually is. 1000 yard shots are very, very difficult.
- In an apocalypse or survival scenario, people are going to be carrying more than the magazine or rounds in the gun. Make sure you reflect they have reloads and how they are carrying them if they are going to be in a firefight.
- Caliber is not a measure of power. It is only a measure of diameter.
- If you’re going to write about guns and never seen, much less handled, one, sign up for an introductory gun safety class at your nearest range that includes live fire. If you can’t do that, get a knowledgeable friend to take you to the range. You will learn more in an afternoon handling real guns than you ever will in imagining what it is like.
By Matt Pickering, Gun owner, engaged in state/national gun policies and politics, instructor/FFL03. He is also a software developer, sailor and sees life as a rogue wave in a quantum sea. Email him at firstname.lastname@example.org if you would like additional information or guidance.
Original question was posed here. There are further pieces of advice in the Comments section on the Quora page. Like “don’t use ‘the smell of cordite.'”