Firearms for the Absolute Beginner: Part 1, the Glossary

Posted On April 27, 2024

—Please read the disclaimer at the end of this article.—

NOTE— This glossary is not presented in alphabetical order.  This is a Progressive Concept Glossary, with each new entry giving the reader a base to build on for the later terms and concepts.  While it is impossible to form such a glossary with no entries requiring knowledge from a future entry to round out the description, in places where that happens I tried to put the entry with the necessary information as close as possible to the one where that information was required.  The student should be able to read the glossary in order and gain greater understanding with each entry.

*Firearm— A mechanical device that uses pressure from burning powder to force a projectile through and out of a metal tube.  BB guns, pre-charged pneumatic guns, or any other gun that uses compressed gas or springs to launch projectiles are NOT classified as firearms by the Bureau of Alcohol, Tobacco, and Firearms (ATF) (although some local jurisdictions are trying to brand those items and everything else that can throw a projectile– including slingshots!– as firearms).  According to the ATF, legally speaking neither is this next entry…

*Muzzleloader— a type of gun loaded by jamming gunpowder and bullet into the same end of the barrel that the bullet comes out of when fired.  This design is hundreds of years old, but has come back into fashion because some jurisdictions have created special hunting seasons when only this type of firearm may be used.  Modern versions are quite accurate and capable of taking any sort of game, but they are extremely slow to re-load.

*Action— The “action” is the heart of the firearm, the moving parts that load, fire, and eject the shells or cartridges.  Muzzleloading firearms have “locks” instead of actions.  See below for descriptions of various types of actions.

*Stock— The back part of a rifle that is held against the shoulder while shooting.

*Barrel— The tube that the projectile is pushed through by the burning powder.

*Breech— The end of the barrel that receives the cartridge before firing.

*Bore— The inside of the barrel.

*Caliber— This refers to the diameter of the bore, but also to other characteristics of the cartridge.  For example, a .22 long rifle, .223, or .22-250 all shoot a projectile of the same diameter, but the cases are radically different, and the projectiles vary in length and weight.  The caliber of most ammunition is stamped on the case bottom, and on the barrel of the firearm.  It is vitally important to match those caliber designations, or the firearm could explode. (See the first comment, below.)

*Muzzle— The end of the barrel that the projectile exits from when shot.

*Trigger— The small lever that is squeezed to begin the firing process.

*Projectile/slug/bullet— The part of the round (see “cartridge,” below) that exits the barrel of the gun.

*Gunpowder— The powdery substance that, when ignited, explodes and propels the slug through the barrel.

*Black Powder— A form of gunpowder that was developed hundreds of years ago, it develops lower pressures than modern powders and generates lots of smoke when ignited.

*Smokless Powder—  Modern gunpowder that does not develop much smoke when ignited.  It is much more powerful than black powder and should never be used in a gun that requires black powder.

*Black Powder Substitute— A modern gunpowder that mimics the properties of black powder, mostly in the area of how much pressure it develops when ignited.  It is harder to ignite than black powder and thus can require stronger percussion caps for ignition, but is considered safer to store and ship.

*Casing/Case— The brass cylinder that holds the gunpowder, the slug, and the primer.  This configuration, which is in near-universal use today, was invented around 1850, and was just beginning to come into military use around the time of the American Civil War (1861-1865).

*Primer— The small round insert in the back of the casing.  When the firing pin hits this insert, a device inside scrapes against the walls of it which creates sparks, and these sparks ignite the gunpowder (“Rimfire” cartridges are slightly different).

*Rifle— A firearm with a long barrel and a stock that is held against the shoulder while firing.  It shoots a round with a single projectile (with a few exceptions), and some are capable of hitting targets at extremely long distances.

*Rifling— The spiral grooves on the inside of rifle and handgun barrels (most shotguns do not have them).  They impart spin to the slug, which keeps it traveling straighter.

*Lands— The raised portions of the spiral grooves in a rifled barrel.

*Grooves— The recessed portions of the spiral grooves in a rifled barrel.

*Carbine— A short rifle that is quicker to point and easier to carry than a longer gun.  They are usually designed to be used on closer targets than long rifles, but are still considered rifles.

*Shotgun— A firearm similar in design to a rifle, designed to shoot rounds that can contain many small projectiles, a few medium-sized projectiles, or a single large projectile.  Most shotguns have smooth bores with no rifling, but some have rifled barrels (those are exclusively used to shoot slugs).  Shotguns are classified by “gauge” instead of “caliber.”  They are close-range weapons, often filled with smaller pellets for hunting small game, or larger animals if slugs (large single projectiles) or buckshot (large lead balls) are used.  Some pistols can fire small shotgun shells.

*Cartridge/round— a “cartridge” or “round” consists of the projectile, the brass casing, the powder, and the primer, properly assembled and ready to load into a firearm.  When the primer is struck, the gunpowder is ignited and the violently expanding gasses propel the slug out of the barrel at high speed.

*Shell— A round that is fired from a shotgun (the term is also used for rounds shot from artillery).

*Centerfire— this refers to a type of cartridge that has a primer in the center of the rear of the casing.

*Rimfire— this refers to a cartridge that has the primer in a rim that runs around the base of the casing.  When any place on this edge is crushed, the priming substance is ignited.  .22 cartridges are rimfire, for example, but historically there have been some big-game cartridges that used this type of primer.

*Firing Pin— a nail-like piece of metal that is propelled forward by a hammer or spring to start the ignition process.  Some firing pins are on the face of the hammer.

*Hammer— The part in a gun that strikes the firing pin with enough force to propel it into the primer and begin ignition.  Some guns do not have hammers, but use springs (“strikers”).

*Firing Chamber— the part of the gun where the cartridge is held in place while the primer is struck by the firing pin.

*Safety— Any mechanism that prevents the gun from being fired. (One of my mentors maintains that sometimes the only safety is the gray matter between the user’s ears.)

*Hammer-block Safety— A mechanism that blocks the hammer from striking the firing pin (or blocks it from striking the primer, if the firing pin is on the hammer face).

*Transfer-Bar Safety— A small piece of metal that needs to be in place in order for the strike of the hammer to transfer its momentum to the firing pin.  Often, the trigger must be actively pulled in order for this transfer bar to be in place, otherwise an inadvertent blow to the hammer (if the gun was dropped, for example) might cause the hammer to strike the firing pin and set off a cartridge.

*Trigger Safety— A small lever built into the trigger itself, which prevents the gun from firing unless that small lever is pressed.

*Grip Safety— A safety built into the grip of a handgun, which prevents the gun from being fired unless the gun is gripped.

*Lever Safety— A lever on the side of a gun that can lock the mechanism or block the hammer, preventing the gun from being fired.

*Button Safety (sometimes called a cross-bolt safety)— A button on the side of the gun that can lock the mechanism and prevent the trigger from being pulled.

*Handgun— a gun designed to be held in one’s hand while shooting.  Some are revolvers and some are “automatics” (see below), and some are even single-shot break-open or bolt-action.  Derringers also fall into this category.  They are usually not as accurate and cannot shoot as far as most rifles, with certain exceptions.

*Revolver— A gun with a cylinder that holds several cartridges, and the cylinder rotates to bring each cartridge into alignment with the barrel and hammer.  The vast majority of revolvers are handguns, but there are some revolver rifles, although those are usually antiques or reproductions.

*Cylinder— The cylindrical piece on a revolver that holds the cartridges and revolves to bring a fresh cartridge in line with the firing pin and barrel for each shot.

*Empty-Chamber Carry— In olden days (from the American Civil War to about the end of the 19th Century), firearms did not have safeties, and revolvers that used percussion caps or modern cartridges with primers (as opposed to very old style flintlocks or matchlocks) could be set-off by a blow to the hammer, which could happen easily if the gun was dropped.  In such revolvers, wise users would always leave one chamber empty, and that chamber was left under the hammer of the gun when it was being carried.

*Bolt-action— A means of firearm operation where a round piece of metal with a handle attached (the “bolt”) is rotated, pulled back, shoved forward to load a new round, and then rotated down to lock the bolt in place before firing.  Bolt-action guns are reliable and usually the most accurate type, but they are slower when firing several shots in a row.  Most bolt-action guns are rifles, but there are some specialized bolt-action handguns.

*Single-action— usually refers to a revolver which requires the hammer to be pulled back with each shot.

*Double-action— can refer to a revolver in which pulling back the trigger also rotates the cylinder and cocks the hammer.  It can also refer to an auto-loading pistol in which pulling the trigger can cock the hammer for the first round in a series.

*Automatic— can mean:

*A pistol that automatically re-loads a new cartridge after each shot, sometimes referred to as “an automatic,” but technically such a handgun is called an “auto-loading pistol.”  Such a pistol requires the trigger to be pulled for each shot.

*A mode of shooting that loads and fires each fresh cartridge “automatically,” shooting continuously as long as the trigger is pulled back and there are still cartridges in the magazine.  Such a mode of firing is usually referred to as “fully-automatic” or “full-auto.”  Fully-automatic guns are not legal for civilians to possess in the United States unless a $200 licensing fee is paid and a special background check is performed for each such weapon purchased.

*Semi-automatic— A gun that fires a round with each pull of the trigger.  While this does somewhat describe a double-action revolver, revolvers are not considered to be semi-automatic.

*There is some discussion about if there is a difference between a pistol and a revolver.  Some insist that a revolver is not a pistol, and only handguns that don’t have a rotating cylinder can be called pistols (except in the state of Texas, but only because they’re stubborn and independent).  Others use the two terms interchangeably.

*Gas-operated—  If a firearm is semi-auto or full-auto, then the mechanism that operates the action is usually powered in one of two ways.  Recoil or blowback-operated guns rely on the recoil power of the ignition to move the mechanism, and gas-operated guns use a small port in the barrel to shunt a small (but powerful) jet of gas into a mechanism that operates the reloading process.  Smokless powder is the technology that allowed this advance, as black powder would clog such gas-operated mechanisms very quickly.

*Magazine— A holder for fresh cartridges that can be pre-loaded and inserted or attached to a gun to re-load it.  In military usage the word can also refer to a place where ammunition and weapons are stored.

*Clip— A holder for fresh cartridges where the cartridges are pushed out of the clip and into the gun to re-load it.  A magazine is not a clip, and a clip is not a magazine.  An exception, in that the cartridges stay in the clip as they are inserted into the gun, are clips that fit an M-1 Garand rifle.

*Straight-walled cartridge— a cartridge that is the same diameter from the base (excluding the rim) to the end where the slug is inserted.  Some jurisdictions have special straight-wall hunting seasons, or completely restrict the hunting of some species to straight-wall cartridges only.  This is because most projectiles fired from straight-walled cartridges will not travel as far as those shot from most “bottle-necked” cartridges, resulting in greater safety.

*Bottle-necked cartridge— A cartridge where the brass casing “necks down” to a smaller diameter where the bullet is inserted.  This can result in a projectile with a smaller diameter and thus less air resistance being fired at a very high rate of speed, which can increase the deadly range.  Such cartridges are often effective at further distances, but with greater chances of a stray bullet traveling farther and causing safety issues.

*Magnum— Originally, a cartridge of greater case size derived from a previous cartridge.  For example, the .44 magnum was derived from the .44 special cartridge.  The magnum cartridge has more powder and generates a higher pressure.  Most firearms designed to fire .357 magnum round can also safely chamber and fire the weaker .38 special round it was derived from (the difference in number is complicated to explain), likewise with the .44 magnum and .44 special.

*Foot-pounds of energy (FPE)— This is a term that describes the amount of energy a flying bullet has.  Many hunters maintain that a small, fast bullet is not as effective at imparting energy to the target as a heavier, large-diameter bullet traveling slower but having the same FPE.  Discussions can get heated about how useful a measurement FPE is, but it is at least a completely objective measurement.  Just don’t think that a .223 is going to have the same stopping power as a .450 Bushmaster, given the same FPE numbers.

More on the history and technological development of Muzzleloaders—-

*Matchlock— The first type of action for firing a muzzle-loading gun.  A slow-burning fuze or punk was held on the end of an S-shaped “tricker,” which was held to the side of the gun with a pin so it could pivot.  When the user wanted the gun to fire he would squeeze the far end of this “tricker” and cause the burning punk to contact a small pan full of gunpowder.  This pan was connected to the firing chamber by way of a small hole in the barrel called a “touch hole,” and when the small pan of powder was set off by the punk, the sparks would (hopefully) go through the touch hole and set off the main charge of gunpowder.  Sometimes the powder in the pan would flash, but would not set off the main charge, giving us the term, “Flash in the pan.”  The matchlock was probably invented around 1400 and in wide use by 1500.  Previous to this, the gun operator or an assistant would have to touch a burning punk to the firing hole by hand.

*Flintlock— Keeping a smoldering punk lit all the time was extremely inconvenient, so those very first breechloading guns were only made ready to fire during a battle.  It was known that when a piece of flint was scraped against metal, sparks resulted.  Thus the “tricker” was replaced with a spring-loaded hammer that held a piece of flint.  A cover, called a “frizzen,”  was developed for the pan which had a curved piece where the flint would hit it.  A hammer with a properly-set piece of flint would, when released (by pulling what was now known as a “trigger”) strike the curved piece of metal, which would cause sparks and simultaneously open the pan, setting off the pan full of powder, and cause a chain reaction as described above for the matchlock.  Because the pan was kept covered, the powder in the pan was relatively safe from the elements, and the gun could be kept in a fire-able condition without requiring a constantly-burning punk.  Flintlocks were invented in the early 1600’s and were still in wide use during the time of the American Civil War (1860-1865), although by then caplocks were invented (see below) and brass-cased ammunition was beginning to be used.  Flintlocks were widely used during the Napoleonic Wars.

*Caplock or Percussion Cap Gun— It was discovered that some compounds could be made to ignite by merely striking them.  Through much experimentation, it was found that a small amount of this substance, called fulminate of mercury, placed in a tiny brass or copper cup could replace the pan and powder, providing a much more convenient and reliable method of igniting the main powder charge.  The open end of the tiny cup was placed over a little hollow cylinder, called a “nipple” or “cone,” and the hole in that cylinder connected the small blast from the cap to the touch hole and thus to the main gunpowder charge.  Many flintlocks could be easily converted to caplock operation.  Eventually the brass cartridge case was developed, and the cap, at that point called a “primer,” was moved to the back of the case.  The caplock gun was invented around 1820.

*Other Types of Muzzleloader Locks— In between the matchlock and flintlock were a number of other designs, from the wheel-lock to the snaphaunce lock to the snap-lock, and several others.  As has ever been the case, firearms makers and users have been modifying older designs and creating new ones to try to make more reliable, efficient, and effective firearms.

*Muzzleloaders were “smoothbore” when they started out, which means that there was no spiral-groove rifling in the barrels. Because of this, they were extremely inaccurate beyond ten yards. In order to overcome this limitation, armies used the strategy of “volley fire,” where lines of men would face off about 70 yards apart, and fire their weapons simultaneously on command. Often, the army that could load and fire their weapons faster often won the battle.

*Muzzleloading Rifles– These did exist (and still do), but because the spiral grooves grabbed on to the bullet very tightly, they were extremely hard and slow to re-load. Their advantage, of course, was that the spiral grooves in the barrel caused the bullet to spin, which drastically increased its accuracy. In the American Revolutionary War rifles were used by specialized troops, often hand-picked sharpshooters.

NOTE—  Mentions made in this essay regarding the ability of various cartridges to take down a particular animal do not address the LEGALITY of hunting the species mentioned with those calibers!  In non-survival situations, always check the state and local hunting laws and regulations before hunting any animal, and always check and adhere to local and federal laws on firearms in general.