A gun is a ranged weapon that fires projectiles by means of a trigger.
A firearm is a gun that uses single instances of the rapid combustion of propellants at the weapon platform.
A rocket gun is a gun that uses ongoing rapid combustion of propellants at projectile.
An air gun is a gun that uses the rapid release of non-combustible propellants. EG: CO2 pellet guns and BB guns.
A rail gun is a gun that uses electro-magnetic energy to propel a projectile.
A stacked gun is a gun that has cartridge-less projectiles loaded nose-to-tail in barrels.
A volley gun is a gun that fires multiple projectiles simultaneously.
A blow gun is a gun that uses blowing.
A crossbow gun is a gun that uses a bow as a propellant.
An electroshock gun or stun gun is an air gun that fires (EG: Taser.com)
A beam gun is a gun that fires energy projectiles. This includes scanning laser guns found at grocery stores but also the typical science fiction blaster guns.
A squirt gun is a lot of fun.
A caulking gun, a scanner gun, etc. are usually used for work instead of combat.
Bows, slings, and slingshots are not guns since they do not use a trigger.
Guns come in different categories.
Smooth Bore v Rifled.
Rifled weapons have 2 or more helical grooves in the bore of the barrel which imparts a spin upon the projectile which provides gyroscopic stability which increases accuracy and effective range.
I do not make the distinction that some make: Guns are smooth bored while rifles are not. Why? There are rifled shotguns and "submachine guns" and pellet guns are also smooth bored. I believe the term "gun" is too broad for just the smooth bore or rifled distinction.
Size. Many long guns are used in hunting but most handguns and all artillery are essentially designed for martial purposes.
Handguns. The handgun is the most modern, most lethal weapon of personal self-defense.
Mid-Length. Guns midway in length between handguns and long guns.
Carbines. Rifled mid-length guns. EG: Colt M4 (a variant of the M16)
Burst-Automatic. 1 trigger pull fires several shots.
Full-Automatic. Holding the trigger down will cause shots to fire continuously.
Machine Guns. Automatic guns with bullet calibers less than or equal to 12.7 mm = 0.5 inch. EG: M2.
Automatic Cannons. Automatic guns with bullet calibers greater than 12.7 mm = 0.5 inch.
Single Action. Releases the hammer or striker. EG: M1911. You have to cock the hammer to set up Single Action for the first shot, but since a shot automatically cocks the gun after firing, subsequent trigger pulls are Single Action.
Double Action. Cocks and then releases the hammer or striker. A Double Action trigger requires more finger force than a Single Action trigger.
Double Action/Single Action. EG: Most versions of the M9 have Double Action for the first shot, but since a shot automatically cocks the gun after firing, subsequent trigger pulls are Single Action.
Muzzleloaders. Usually the ammo is loaded through the front end of the muzzle or barrel of the gun. Single-shot. EG: Early muskets and mortar cannon.
Breechloaders. The ammo is loaded at the back end of the muzzle or barrel of the gun.
Hinges or Breaks Opens. The gun folds open at the breech for loading. EG: Over-and-under or side-by-side shotguns.
Bolt Action. The ammos is manually loaded and locked by a rotating bolt. Bolt action is still standard for sniper shooting. Single-shot.
Revolver. The ammo is fed into the chamber by a rotating cylinder. Not popular for long guns since the discharge was too close to the face. Semi-automatic.
Lever Action. The ammos is fed into the chamber by cranking a lever (usually part of the trigger guard) with the trigger hand. Semi-automatic.
Pump Action. The ammos is fed into the chamber by a pumping part of the gun grasped by the non-trigger hand back and forth. The rearward motion opens the action, extracts and ejects the spent casing, and allows a fresh cartridge to move from the magazine to the chamber area. The forward motion seats the new cartridge into the chamber and closes the action.
Magazine Fed. The ammos is fed to the barrel by a spring-loaded case. Magazines come as straight (EG: M16), curved (EG: AK47s), circular (EG: Tommy Guns), and other variations. Semi-automatic, burst, or automatic.
Belt Fed. The ammos is strung on belt that is fed to the barrel. Usually automatic.
Gatling Action. The barrels rotate as ammo is fed. The rotation comes from external power (like a hand crank or electric motor) as opposed to internal power (from the ammo itself).
Fuse Lit. No "trigger" involved here.
Matchlock. When the trigger is pulled, a lit cord is rotated forward.
Wheellock. When the trigger is pulled, a pre-wound wheel spins against flint causing a spark.
Flintlock. When the trigger is pulled, a cocked hammer with flint slams against steel (the "frizzen") causing a spark.
Percussion Caps or Primers. Instead of a weather-sensitive flash pan, a shock-sensitive propellant is placed in a disposable cap and hit by a triggered hammer.
Cartridge. Finally! The bullet and propellants were encased as one unit and hit by triggered hammer. A single cartridge (aka a complete round, or a single unit of ammunition) consists of several basic parts. Note that the term "ammunition" covers modern rounds but for older weapons, it also includes the fuses and gunpowder. For air guns it would also include external propellant.
Case, casing, shell. This is a sheath holding the other parts of a round.
For most guns this is a thin metal like brass.
For shotguns, the shell is usually paper or plastic with a metal base. Additionally, a shotgun shell may contain a wad (inner container) for holding the shot.
Primer. This is the ignition component of a round. The primer is usually found at the base (head) of a round. Primer are mostly made up of metallic fulminate or lead styphnate.
Centerfire rounds. Thhe primer is in the center of the base.
Rimfire rounds. The primer is in the rim of the base.
Dummy rounds. There is no primer.
Propellant, gunpowder. A chemical substance which is ignited by the primer that expands so rapidly that it propels the bullet. Modern powder is largely smokeless and is usually primarily composed of nitroglycerin and nitrocellulose.
Bullet. The projectile that is expelled from a gun. This is the only part of a round that leaves the gun. Some bullet variations:
Different materials. EG: Lead, steel, rock salt (ala Kill Bill), depleted uranium. EGs:
Blunderbusses were usually filled with bits of whatever was available.
Softer materials such as rubber can be used when lethality is not desired.
Modern hunting bullet are often made out of steel instead of lead in order to avoid lead poisoning.
Tracers have material at the rear of the bullet that flares during flight.
Jackets. Jacketed bullets are covered and prevent the bullet from deforming until impact.
Soft or Hollow points. The jacket does not cover the front or tip of the bullet.
Armor piercing. The jacket material is a very hard and dense material.
Bullets per Cartridge.
Single Bullet. Most guns fire single bullets. If a shotgun fires a single bullet, then the bullet is called a "slug".
Multi Bullets. Shotgun ammo usually consists of multiple bullets per cartridge. The little bullets are aka "shot" or pellets.
Zero Bullets. Blank rounds have no bullet, but make a good noise.
The most common size given for a gun or round is the caliber, the nominal diameter of the gun's bore.
The US uses 1/100ths of an inch for caliber. EGs: .22, , .357, .44, .45, .68 (paintball)
Some times the caliber is combined with other info.
EG1: .30-06. The "06" refers to the year of the gun's introduction.
EG2: .30-30. The 2nd 30 refers to the weight of the bullet in grains.
Everyone else uses millimeters for caliber. EGs: 7 mm, 9 mm.
Magnum refers to a longer round of the same caliber.
While the caliber is very important, there are other factors to take into account including the weight of the bullet, the terminal ballistics, and the charge of gunpowder.
The most popular calibers from the smallest to largest:
22 Long Rifle, aka 22 LR. 5.56 x 15 mm = 0.22 x 0.59 in. The most popular. For rifles and handguns.
5.56 mm NATO (see below). 5.56 x 45 mm = 0.22 x 1.76 in.
7.62 mm NATO (see below). 7.62 x 51 mm = 0.30 x 2.00 in.
0.30-30 Winchester. 7.62 x 51 mm = 0.30 x 2.00 in.
9mm Parabellum (see below). 9.00 x 19 mm = 0.35 x 0.87 in.
40 Smith & Wesson. 10.00 x 22 mm = 0.39 x 0.87 in.
45 Automatic Colt Pistol (ACP) (see below). 11.43 x 23 mm = 0.45 x 0.91 in.
Shotguns have several measurements.
The barrel diameter of a shotgun and the diameter of shotgun cartridges/shells is measured in a primitive unit called "gauge". If there were a ball whose diameter was the same as the bore of a shotgun, then the the number of these balls it would take to make a pound would be the gauge of that shotgun.
*The most common shotgun gauges.
Larger sizes are needed for larger targets or farther targets or both.
20 to 12 for small (Teal, Bufflehead) to medium (Wood, Widgeon) ducks
20 to 10 for large ducks (Mallard, Pintail)
12 to 10 for medium (Snow, Lesser Canada) to large (Giant, Western Canada) geese.
The diameter of shotgun shot/pellets is referred by number called "shot size". Like gauges, smaller shot number means larger shot size. Steel shot is lighter than lead shot, so with steel you need slightly larger shot sizes than lead.
The most common sizes (smaller to larger) are: 8, 7, 6, 5, 4, 3, 2, 1, BB, BBB, and T.
If a shotgun fires a single bullet, then the bullet is called a "slug" and there are not shots.
This size or smaller for home self-defense if property damage is an issue.
As in BB guns. 4.425 mm & ~.3 g. Airsoft BBs are 6 or 8 mm and .12 to .45 g.
This size and below is "birdshot", above is "buckshot".
This size (no larger or smaller) for deadly force if property damage is not an issue. [Ref]
"triple ought buck"
The number of pellets per shell is called "shot charge". So called "magnum" shells have greater shot charge than regular shells.
The length of shotgun ammo is measured in inches. The standard ammo length and chamber size is 2 3/4". Magnum chambers (3" or 3 1/2") accept its specified size or smaller. Many states require that shotguns have no more than 3 rounds loaded when hunting, thus many shotguns come with a "plug" to prevent the loading of more than 3 rounds. The other common size is 2 1/2".
The cone (aka spread, shot pattern) produced by a shot gun is affected by the "choke", i.e. the taper of the barrel, esp. the difference between the bore diameter and the muzzle diameter. [Ref, Ref, Ref, Ref]
Do not use steel shot with full chokes or tighter unless the guns specifies that it accepts steel shot.
The most popular chokes are Cylinder, Improved Cylinder, Modified, and Full.
In 30" Circle
40% at 40 yards
No choke at all. Aka Cylinder Bore.
50% at 25 yards
50% at 40 yards
60% at 40 yards
70% at 40 yards
80% at 40 yards
Shotgun barrel lengths are traditionally 20", 21", 23", 26", 28", or 30". The barrel length does not affect the weapon range but it does affect aiming and mounting agility.
The amount of propellant in a round is usually measured in several ways. Here they are, listed from heaviest to lightest:
drams =1/256 lb = 1/16 oz = 1.7718452 g = 27.34375 grains
g = 0.00220462262 lb = 0.0352739619 oz = 0.564383391 dram = 15.4323584 grains
grains = 1/7000 lb = 0.00228571429 oz = 0.0365714286 dram = 0.06479891 grams
mg = 0.0154323584 grains
Dram equivalents is a measure of the explosive power of a propellant in drams of gunpowder. 1 dram of gunpowder = 1 dram equivalent. 1 dram of modern smokeless gunpowder may be more than 1 dram equivalent.
Gun Safety Rules
These should be thoroughly reviewed all the time.
Act as if every gun is always loaded.
Don't ever point it at anything you're not willing to destroy.
Always keep your finger off the trigger until you’re ready to shoot the gun.
Rifle that take the same rounds and magazines as common handguns. EG: The Beretta Cx4 Storm takes 9mm rounds in 92 magazines, 40 S&W in 96, and .45AEP in 8045).
Rifles that shoot different kinds of rounds. EG: The Russian Baikal 12H-94 is a hammerless breaking over-under rifle/shotgun that has .22 on top and .410 on the bottom. Only $199!
The most common U.S. military guns, by bore.
5.56 mm = .223 inch x 45 mm = 1.77 inch NATO cartridge. Except for the M249, all of these guns happen to be in the AR-15 family.
M16 and M16A1 rifles. Effective range 200 m = 215 yards. 20-30 round magazines. Semi-Automatic and Full-Automatic. Derived from the ArmaLite/Colt AR-15 which was originally 7.62 mm.
M16A2 and M16A4 rifles. Like the M16. The primary difference is that it is Semi-Automatic and 3 round Burst-Automatic. 100 cm = 40 inches long. 4 Kg = 8.8 pounds with 30 round magazine.
M4/M4A1 carbine. Like the M16A2 but shorter.
M249 light machine gun. Squad Automatic Weapon (SAW). Effective range 800 m = 900 yards.
7.62 mm = .308 inch x 51 mm = 2.00 inch NATO cartridge.
M60 medium machine gun. Full-Automatic. Belt fed. Effective range 1100 m = 1200 yards.
M240 medium machine gun. Full-Automatic. Belt fed. Effective range 1800 m = 1970 yards. Replacement for the M60.
There are many sniper/marksman rifles that use this caliber. Most of them are Bolt-Action or Semi-Automatic.
M40, M40A1, and M40A3 sniper rifles. Bolt-Action. U.S. Marine standard since 1966. Effective range 900 m = 1000 yards.
M24 SWS (Sniper Weapon System). Bolt-Action. U.S. Army standard since 1988. Effective range 800 m = 900 yards.
9 mm = .354 inch x 19 mm = 0.748 inch cartridge.
M9 handgun. Beretta 92. Semi-Automatic. 10-30 round capacity. Replaced the M1911. Unloaded weight ~.950 Kg = 2.1 pounds
M11 handgun. Sig P226. Semi-Automatic. 15 round capacity. The other second choice replacement for the M1911. Unloaded weight ~ .800 Kg = 1.8 pounds.
11.4 mm = .45 inch x 23 mm = 0.905 inch Automatic Colt Pistol (ACP) cartridge.
M1911 handgun. Made by Colt's Firearms, designed by John Browning. U.S. military standard from 1911 to 1985. The previous standard of .38 was found insufficient to stop the Moro insurgents during the Philippine-American War. Newer versions may actually be 9mm but that's cheating. 7+1 round capacity (but may go up to 9+1 for newer versions). Unloaded weight ~1.1 Kg = 2.4 pounds.
12.7 mm = .50 inch x 99 mm = 3.897 inch cartridge.
M2 heavy machine gun. Aka Ma Deuce. Designed by John Browning. Full-Automatic. Belt fed. Effective range 2000 m = 2200 yards.
18.5 mm = .729 inch = 12 gauge shotgun.
M1014 combat shotgun. Aka Benelli M4 Super 90. Pump action.
Mossberg 500A combat shotgun.
40 mm = 1.57 inch grenade.
M203 grenade launcher. Effective range pointing 150 m = 160 yards. Effective range area 350 m = 380 yards. Can be fitted on the M16 family and the M4 family.
84 mm = 3.31 inch rocket.
M136 AT4 light anti-armor weapon. Disposable. Effective range 250 m = 270 yards.
Airgun ballistics. Assuming Kinetic Energy = 0.5 * m * v^2, and enter an equation like this in Google: .5*.34*600^2 g*feet^2/s^2 in J.
BB gun pellets are usually steel
0.177 in = 4.425 mm, 5.3 grain = 0.34 g, 600 f/s = 340 m/h = 150 m/s, 5.69 J
There are other issues such as the material of the pellet, penetrative pressure (esp. the issue of similar force over a smaller area), velocity reduction via drag (esp. pellets slow as they they travel further), where you get hit, whether you have protection, etc.
All I need now is equipment and volunteers to get shot up in a variety of ways to complete the experiment.
1) See the target. 2) Align the firearm with the target. 3) Keep that alignment while the trigger is pulled.