Learn More About Guns
Designation for ammo that is overloaded to make it slightly "hotter" (more powerful) than the standard for
that caliber. Typically available for 9mm, .45 cal, and .38 Special. Not all guns are built to withstand
the higher pressures, so check your owner's manual before using any +P.
NOTE: while some manufacturers sell .380 +P, there is no recognized standard for that caliber. Using it could damage the gun.
A generic term for a full-sized pistol with a shape similar to the iconic Browning Model 1911.
6 o'clock hold
For complicated reasons of physics and ballistics, a bullet does not travel in a completely straight line.
At 10 yards or less, the difference is generally too small to measure, so this is more important for
rifles than pistols, but even a pistol will display this error at 15 yards or more. A gun that shoots to POA
(point of aim) at 7 yards may shoot several inches high at 25 yards. Most people don't shoot a pistol at
25 yards, but if you do, and this happens, aim below the target zone. If the target is round, like a bullseye,
envision it like a clock, and aim at the bottom (6 o'clock). This is also called "pumpkin on a fencepost".
A relatively uncommon caliber intended to graft the ballistics of the .357 Magnum revolver onto the autoloader platform. Think of it as
a .40 caliber on steroids. It is becoming increasingly common as a police sidearm. It was developed by the Sig Sauer company.
The Armalite Rifle, developed in the 1960s by the Armalite Corp to replace the aging M-1 combat rifle.
It featured a shorter barrel, an adjustable stock, 20 round removable magazine, a built-in shock absorber,
select-fire, an easier take-down process, and a smaller but faster bullet. It was labelled the
M-16, and production was eventually taken over by Colt. The AR-15 is the civilian version of the M-16,
and does not allow for select-fire. The AR is considered a "platform" rifle, in that, while they are
manufactured by hundreds of companies, they all have identical operational controls, and similar features.
More properly called a "breaching rifle", this is a short, select-fire rifle, capable of both semi-auto
fire and full-auto or burst mode (sub-machine gun). These are illegal for civilians to own, except for
people (mostly collectors) with a high degree of trust from authorities, and include weapons like
the American M-16 and M-4, the Israeli Uzi, and the German Hechler & Koch MP5. They cost thousands
of dollars, and require as much as a year of Federal paperwork and background checks to acquire.
The AR-15 and AK-47 are not breaching rifles, but standard semi-automatic rifles, similar in function
(though not appearance) to common hunting and target rifles.
Another term for a semi-automatic pistol.
At a firing range, the obstacle behind the target that keeps the bullets from leaving the range and
possibly causing damage or injury elsewhere. It can be a hill or high mound of earth backed up with concrete blocks,
or a slanted concrete floor that guides bullets up into an overhead construction to minimize ricochets. Never try to
shoot over the backstop, and be very wary of shooting anywhere without a suitable backstop. A stray bullet can
travel hundreds of yards.
The rear part of the pistol grip, facing your palm. Some models have interchangeable backstraps, which can
change the overall size of the grip to fit smaller or larger hands. When the grip is too big for your hand,
there may be a tendency to address the trigger laterally, and cause shots to go left. When the grip is too small
for the length of your fingers, you may put too much finger on the trigger, and pull right.
A sharp outward curve of the back of the grip just below the hammer or back of the slide. It fits into the
soft fleshy part of the hand between thumb and index finger. It keeps you from getting your hand too high
and getting caught by the mechanism. That said, your hand should be as high on the gun as possible, without
trying to get above the beavertail.
The point at which the trigger releases the hammer or striker.
The metal slug at the front of a cartridge; the only part that travels through the barrel and out the muzzle.
The measurement of the bore of the barrel; used to describe both the pistol and the ammo it shoots,
i.e., .40 cal = 4/10 inch. For historical reasons, some caliber designations are not technically
correct: both .38 and .380 are not correct, for different reasons. We just have to live with it, like
the fact that Columbus did not discover America.
Often confused with bullet, this is the entire cartridge that holds the bullet and powder.
The part of the cartridge that is left after the bullet is shot out of it. They are reusable, and used by people who reload their own ammo.
With the exception of the few rimfire calibers, most cartridges have the primer located in the center of the base of the casing.
The firing pin has to strike the cartridge in the center to fire it.
The only section at the rear of the barrel that is large enough for the cartridge. The cartridge is fired in the chamber, but stays
there until removed, while the bullet travels down the barrel. An autoloader only has one chamber, while a revolver has 5-7 chambers in a rotating cylinder.
Acronym for Concealed Handgun License, known in some jurisdictions as CCW (Concealed Carry Weapon). See LTC.
The act of removing the magazine and extracting all cartridges from an autoloader, or removing all cartridges/casings
from a revolver, thus making it obvious to a witness that the pistol is completely safe. One should always clear a pistol/rifle before stepping
away from the firing line, before carrying the gun (cased or uncased) anywhere, or before handing it to someone.
Not a magazine. See moon clips and stripper clips.
In a revolver, the cylinder holds the 5 (to 7) chambers, into which are inserted the cartridges.
When a pistol (that has an external hammer) is in single-action mode, the shooter should not stop for any significant amount of time without
letting the hammer back down. Since most people do not know how to decock a pistol properly, some guns come with a decocking lever which
will do this safely.
Double stack magazine
A wider than normal pistol magazine that allows cartridges to load in an overlapping fashion, with the
result that the magazine holds more ammo than its height would suggest. The pistol grip has to be wider
to accept it. Sometimes these pistols are harder to conceal, due to the added width. Many people think
that is a good trade-off, since it carries more ammo than a similar single stack magazine.
The trigger performs two actions: cocking the hammer against a spring, and releasing same to fire the round.
Practicing trigger pulls without ammo. A very good exercise, but should not be done with rimfire guns, unless the
manufacturer states that it is safe for the gun. Otherwise, damage could occur.
On a semi-automatic, the opening in the slide on the right side of the gun through which empty casings are ejected during the
firing sequence. These casings will sometimes hit you in the face (hence the need for eye protection) or go down your shirt, and they will
definitely hit the person to your right, unless there is a baffle in place. They are not dangerous, just annoying.
Up and down adjustments in aiming, while left and right adjustments are called windage. All scopes have
windage and elevation fine adjustments. Most rifles and some pistols have windage adjustments possible
(although some are tricky). Pistols typically do not have elevation adjustments
available, except for target pistols.
Slang for Eye Protection and Ear Protection, both of which are required at gun ranges.
Federal Fireams License. A Class 1 licensee can buy guns wholesale and sell them retail. While all gun stores
have a Class 1 FFL, many such licensees are individuals who work from their homes. There are substantial
paperwork requirements, overseen by the ATF. A Class 3 FFL is for firearms collectors. They cannot deal in
firearms as a business. The paperwork is less, but the process of acquiring items for the collection
Firing Pin Safety Block
An internal device present on many semi-automatics which prevents the gun from being discharged unless the trigger has been
depressed. Dropping such a gun will not cause it to fire. In fact, most handguns have multiple internal
There is an acquired skill of quickly pointing a gun, getting a sight-picture, and firing, without taking time to carefully align the sights. The
purpose is defensive shooting. Experience and instinct are required.
In general, continuing to maintain all aspects of the fundamentals (stance, arm-extension, grip, etc.) past the point at which the
shot breaks. More specifically, continuing to pull the trigger back past the break until it hits the frame. In both cases, the goal
is to minimize any influence on the muzzle during the shot.
Full Metal Jacket. Ammo where the bullet is enclosed in copper or zinc alloy, so no lead is exposed. These are less expensive
than HP, and have greater penetration (sometimes too much).
In an autoloader, the shell just fired is automatically ejected out of the right side.
If it doesn't eject at all, that could be a light primer strike, a worn extractor hook,
or dirt behind the extractor. If it ejects enough to get caught by the slide returning
to battery, that could be a too-strong recoil spring, or dirt in the slide rail, but is
often related to not having a firm enough grip on the pistol (see Limp-wristing).
A unit of weight for bullets (bullets, not cartridges), equal to 1/7000 of a lb. Heavier bullets
move slower and drop more, but can impart greater force. However, the slower velocity mitigates the
increased force. See Power Factor.
Both the portion of the pistol that you hold, and the way in which you hold it. Both are important.
On 1911 pistols (and some others), a pressure point on the backstrap keeps the gun from firing unless it is held properly. It cannot fire if dropped,
unless the grip safety is defective. Any type of safety can fail, although they seldom do.
Bullets with a hollowed out tip, which causes them to expand in flight, and expand more on contact.
The media typically thinks these are "cop-killer" rounds, but the intention is actually safety.
The larger profile prevents over-penetration, which could cause a bullet to go all the way through a person
and hit someone behind them. They were developed at the request of police agencies, to protect the
public. A side-benefit is that they cause more surface damage, thus stopping an active shooter sooner.
A device for carrying a handgun. Usually made of leather or Kydex (a plastic-like material), and
sometimes fabric or latex, these are important for protecting the trigger guard so nothing snags
the trigger. They can be classified as "Inside-the-waistband" (IWB), "Outside-the-waistband" (OWB),
i.e., open-carry, pocket holster, shoulder holster, ankle holster, bra holster, or "belly-band".
There also exist holster purses for ladies, with a zipper pocket to keep a gun isolated from other contents.
Keeping the index finger of the shooting hand always straight alongside the frame of the gun, and never inside
the trigger guard, until a sight-picture is acquired.
Inside the WaistBand, a holster that fits between the belt and body, so the gun is inside the
pants. Some models are "tuckable", meaning a shirttail can be tucked between the gun and the belt,
so nothing can be seen except the metal hooks on the belt.
A rigid, plastic-like material frequently used for holsters. Thy are molded for each model of gun,
so the gun tends to "lock in", providing both retention capability, and one-handed reholstering.
Law Enforcement holsters are almost always Kydex.
An aiming device used on military sniper rifles, but also on many handguns, often as an aftermarket
add-on. It projects a red or green laser light beam onto the target, and assists in aiming. They
have to be zeroed like a scope. They are often limited in range, and can be impossible to see in daylight.
Common acronym for Law Enforcement Officer.
The proper operation of a semi-automatic requires a minimum amount of recoil from the exploding cartridge
to drive the slide back, eject the shell casing, and drive another cartridge into the chamber. If the shooter allows their arm/wrist
to act like a spring, some of that force is absorbed, and the slide may not move back far enough to eject the casing.
This leads to malfunctions.
Acronym for License to Carry, formerly known as CHL.
An iconic German pistol of the 1930s-40s, but also a label to describe traditional 9mm (Parabellum) ammunition.
Never buy 9mm ammo that is NOT labeled "Luger" without a valid reason (see Makarov).
A detachable container that holds cartridges; not a clip.
Not a private detective, but a cartridge designated to have more powder in it, to produce substantially
more muzzle velocity and energy transfer (and recoil). Common examples are the .357 Magnum revolver
(much hotter than .38 Special), .44 Magnum (much hotter than .44 Special), and .22 WMR (Winchester
Magnum Rimfire), which turns a .22 LR into a rocket. Note that, while the .357 Magnum and .44 Magnum can
safely shoot their lesser cartridges, the .22 Magnum cannot.
An unusual variant on the 9mm (9x19) cartridge, the Russian Makarov is slightly shorter (9x18). It should only be
fired in a pistol specifically chambered for the Makarov round.
Minute-of-angle. A ballistics term used to describe the fact that any error between POA and POI
increases with distance to the target. Applies to any type of gun, but is most often used with rifles at
100+ yards. However, pistol shooters should be aware of the issue.
Revolvers require cartridges with rims, so they don't slip through the chambers. Some revolvers are
chambered for non-rimmed calibers normally used in semi-automatics (like .45 ACP), so these guns require
a metal clip to keep the cartridges in place.
The business end of the barrel.
A pistol or rifle that is about 200 years old, or is a replica of same. These were loaded through the muzzle (the front end),
with black powder, then a cloth or paper patch, then a lead ball. That was tamped down with a rod. The ball is typically 50 caliber or bigger,
and quite powerful. These replica guns are readily available and very popular for sporting and plinking purposes, but care
must be taken, as black powder, unlike gunpowder, is explosive.
Pistol sights utilizing three dots containing a substance like Tritium that glows in the dark.
While useful for a nighttime emergency, they will lose their glow after a few years. Seniors
may not appreciate the small size of the dots.
Carrying a pistol in a holster that is not concealed from public view. A license is required to do
this in almost all states.
The distance the trigger travels after the shot breaks. Less is better. This is sometimes adjustable.
Outside the WaistBand, a holster worn in plain view, like a Police Officer. These are legal in Texas if you
have an LTC, subject to certain restrictions.
Slang for fun target shooting, using paper targets, bottles, cans, melons, etc.
Point of Aim. Where you want the bullet to go.
Point of Impact. Where it actually went.
Shooting without using the sights at all, using specific techniques. This takes practice, and is only viable
at very short distances, 3 yards or less.
A calculated number that indicates, in a relative way, the stopping power of a particular cartridge.
Stopping power is proportional to both bullet weight and velocity, but those two values are inversely
proportional to each other (heavier bullets travel slower), so Power Factor is a metric that takes both
into account, with this formula:
pf = w x v / 1000
Power Factor = Weight (in grains) x Velocity (fps) / 1000
A 165 gr bullet traveling at 1100 fps = PF 181.5
A 180 gr bullet traveling at 960 fps = PF 172.8
The two examples above are both .40 cal, but in this case, the lighter bullet hits marginally harder, with less recoil.
A small, concussive detonating device mounted in the base of a cartridge. It is set off by a sharp strike from
a small, pointed object, and causes the powder in the cartridge to ignite, generating a large amount of gas. This propels the bullet down
Verb, to pull back the slide on a semi-automatic and allow it to spring forward, loading a cartridge from
the magazine into the chamber. Some degree of hand strength is required.
A popular aiming device often used on rifles, and sometimes pistols. It does not project a laser beam
to the target (see Laser), but instead projects a red dot onto the image of the target inside the
device itself. Consequently, neither distance to the target nor sunlight have any affect on it. It
does have to be zeroed like a scope, although it does not magnify the image.
When firing a semi-auto pistol, keep pulling past the break until it bottoms out on the frame. Then let up
just a few millimeters until you hear a "click". You are now at the sear wall, and the sear has reset
so that you can fire again without lifting your finger off the trigger. "Riding the reset" is a good
Retention holsters have special features that make it difficult for someone to grab your gun by force.
These can include a thumb strap, the FBI cant (15 degree tilt), and a locking mechanism (Kydex holsters only).
Holsters with any of these features are available to civilians, and are usually required for law enforcement
A spiral groove cut into the bore of the barrel. This imparts spin to the bullet and contributes
to greater accuracy, especially with rifles. It is similar to the spin of a football. Lighter or
heavier bullet weights require different rates of twist of the rifling for greater efficiency.
Due to the small size, .17 and .22 caliber guns (pistols and rifles) have the primer embedded in
the rim of the base of the casing, instead of the center. The firing pin has to hit the cartridge
on the rim to fire it. Consequently, dry-firing guns of this type may damage the firing pin, as,
without a shell casing in the way, the firing pin would hit the edge of the chamber.
Range Safety Officer. An individual with specialized training for managing a firing line with
multiple shooters. If the number of people shooting is more than about 8, he may have some
assistants. Always used at outdoor ranges, and often at indoor ranges. The RSO has a critical
role in establishing and maintaining a set of rules and policies that will keep everyone safe.
He/she has full authority to remove someone from the range if necessary. They are usually armed,
for good reason.
A mechanical device on some semi-automatic pistols which prevents the pistol from shooting. While failure of this device
is quite rare, you should never trust it with your life. They are usually mounted near the right thumb (ambidextrous safeties can be reached with either thumb),
but are sometimes built into the grip (grip safety), so that the pistol has to be held properly to be fired.
Hammer-fired pistols will always have either a safety or decocker. Striker-fired pistols, having less
sensitive triggers, may or may not. The models carried by police seldom have safeties.
Often used on rifles, but seldom on pistols, a scope magnifies the target from 3 to 15 times or more.
Crosshairs assist in aiming. They can be quite expensive, often costing more than the gun, and
require zero calibration at a specific distance. That is best done by an expert.
The part of the trigger mechanism that holds the hammer or striker back until sufficient pressure
has been applied to the trigger, at which point the hammer or striker is released to strike the
firing pin and discharge the weapon.
On semi-auto handguns with two-stage triggers, a point about 2/3 of the way through the trigger
stroke where there is a stopping place, or "curb". Moving to this point is called "preparing the
trigger". From this spot, exerting more pressure causes the trigger to ease over that curb to
the break, which fires the gun. Doing this gently allows you to fire the gun without letting
the muzzle move off the target.
Combat rifles have a rotary switch on the left side, operated by the thumb, which allows the operator to
"select" semi-auto mode or full-auto (sometimes burst mode). By Federal law, models available for purchase
by the general public cannot have this feature. They are, however, used by law enforcement and the military.
The distance from the rear sight to the front sight. The shorter the sight-radius, the higher the degree of
aiming error, multiplied by the distance. That is why longer-barreled pistols (and rifles) are more
accurate at longer distances.
AKA Iron Sights. The front and rear sights permanently attached to most pistols. They are
usually adjustable, although sometimes not easily.
The combination view of rear sight, front sight, and target. The components must be aligned properly.
Single stack magazine
A slender pistol magazine that accept cartridges only in a vertical stack. These hold less ammo than
a double stack magazine, but that allows the grip to be thinner, often an advantage for concealability.
When a pistol is cocked, and only a short trigger pull is required to fire it, it is said to be in
single-action mode. Some pistols (revolvers) have to be manually cocked to be in this state, while
some autoloaders are always in single-action mode after the first shot. Striker-fired guns are always
On an autoloader, the upper part of the gun, which moves back and forth on rails to load and eject cartridges.
One should keep their hands away from the slide while firing.
If you put the support-hand thumb behind the slide on an autoloader, you are likely to be struck by the
slide as it cycles. It is not fatal, but hurts a lot, and tends to bleed profusely. People tend to
only be "bitten" once, as they quickly learn a valuable lesson.
Dummy cartridges used to test the action (loading/unloading) of pistols. They do nothing at all, and are often
painted a bright red or blue.
For semi-automatics, a device for assisting in pushing cartridges down into a magazine. Almost mandatory
for some pistols. For revolvers, a device that holds 5 or 6 cartridges for quick insertion into the cylinder.
The basis of your shooting platform; the way you stand and position your body. The Weaver
stance was in common use by law enforcement for many years, but that has largely been replaced now
by the Isosceles stance.
Bullets are traditionally made of lead, and often coated with copper or zinc compounds. Steel-core bullets
are made of steel. They are not more lethal, just cheaper. They are banned by many ranges, as they pose
a fire hazard from sparks when they hit concrete.
Where hammer-fired pistols use an external hammer to drive the firing pin into the rear of the cartridge,
firing the primer which ignites the powder in the cartridge, striker-fired pistols have a firing pin that
is spring-loaded. Racking the slide puts partial spring pressure on the striker, but not full pressure.
Pulling the trigger adds the additional spring pressure necessary to fire the gun. While it may not be accurate
to say that striker-fired guns are safer than hammer-fired ones, it is safe to say that they are more
"idiot-proof". They never have decockers, and seldom have safeties, so there is nothing to remember:
just point and shoot (if it has been racked). Many modern pistols are striker-fired, like Glock, some Smith & Wesson, Springfield Armory,
Ruger, and others. More traditional pistols, like CZ (and clones), Beretta, SIG Sauer, Kimber, and all 1911s
Typically used in WWII combat rifles, these clips hold a stack of 5-8 cartridges together. The assembly
is pushed into the rifle from the top, as the magazine is non-removable.
Slang for an ejected casing that gets caught by the slide before it is fully clear of the gun (see FTE).
Bullets that travel below the speed of sound (1125 fps) do not break the sound barrier, so are quieter.
These are primarily .22 and .45 caliber, although even those may be overloaded with powder, or use
lighter bullets, to reach supersonic speeds. The length of the barrel is also a factor, as longer barrels
generate more speed. This is mostly important to people who use a suppressor, since the loudest component
of a gunshot is the crack when the bullet breaks the sound barrier. Subsonic .22 rounds, fired through a
short barrel, and through a suppressor, can be almost inaudible.
A cylindrical device that screws onto the end of a pistol/rifle barrel to reduce the sound of a gunshot.
It does so by diverting the gasses from the muzzle blast through a series of baffles. Also known as a
silencer (or can), these are regulated by the ATF, under the provisions of the National Firearms Act of 1934.
They are legal to own, but require a lot of paperwork that takes at least 6 months. They are most effective
with rimfire calibers.
Sweeping the line
On a firing line, turning around (or to the side) without properly controlling the muzzle, so that it passes across one or more people.
This is extremely dangerous, a huge breach of protocol, and will often result in you being ejected from the range. It will also cause you
to be treated like a moron. The muzzle must always point downrange. Serious shooters are always
conscious of this.
A sense that events have gone into slow motion, frequently encountered by people in gun fights. This can
lead to confusion in police statements, which in turn can be interpreted as the shooter "changing his story".
Defining an exact timeline should always be delayed for one sleep cycle.
The distance the trigger travels before contacting the sear. Less is better for target shooting,
but more is better (within reason) for safety purposes.
A high powered Soviet cold-war period pistol round (7.62x25), and used generically as a label for guns that
fire this round. It is smaller than a 9mm, but much more powerful. Originally Russian, the TT-33 pistol was,
after WWII, produced in all the Soviet-bloc and Warsaw Pact countries (Poland, Romania, Hungary, Yugoslavia,
China), and then imported into, or manufactured in, many other countries. Almost identical copies of the
Polish/Romanian/Chinese Tokarevs can now be found in Egypt, Syria, Libya, Pakistan, central Africa, Viet Nam,
and other parts of the Pacific Rim. Although it has many of the design features of the iconic John Browning
1911, it is relatively rare in the U.S. Nevertheless, it is one of the most prolific models of pistol in the
Normally only used in machine guns, where every fifth round is coated with magnesium. Friction from the
air makes them glow, so the gunners can see the path of fire. They have no useful purpose for
civilians, but they have started fires at ranges. They are always banned from civilian ranges,
but sometimes an idiot will sneak some in.
The lever that releases the hammer/striker to strike the back of the cartridge. You must not touch
the trigger until you are in position to shoot. The trigger guard protects the trigger
from being snagged by clothing or holsters.
Slang for a revolver.
Left and right adjustments in aiming, while up and down adjustments are called elevation. All scopes
have windage and elevation fine adjustments. Most rifles and some pistols have windage adjustments
possible (although some are tricky). Pistols typically do not have elevation adjustments
available, except for target pistols.
Without getting too deep into the physics, an aiming device (scope/laser/red dot) cannot operate on a
plane parallel to the plane of the bullet path (itself not flat), or the POA and POI will never
intersect. Instead, the aiming plane is angled to intersect the plane of the bullet, at a specific
distance, often 100 yds (rifle) or 25 yds (pistol). Consequently, the POI will be either high
or low at other distances, so the shooter has to adjust manually.
Technique for using a small caliber pistol (.22/.32) in a defensive situation. Inasmuch as these rounds
have little stopping power, instead of shooting 2-3 times to the same area, shoot 6-10 times rapidly
in a pattern from the chest down to the lower torso, the "zipper" effect. If the wounds are not
fatal, the bad guy will at least be in serious trouble, as he will be bleeding from multiple
places, and will not be able to stop the bleeding easily. This technique was developed by
partisan guerillas during WWII for taking out sentries at Nazi locations like railway stations
and ammo dumps.