Guns for Beginners: Anatomy of Ammo

For some people who haven’t been exposed to firearms, it can be a mystery as to exactly how ammunition works.  We even see in TV and movies, some people still suffer under the mistaken belief that the entire cartridge fires out of a gun’s barrel.  This article will be for those who are entirely new to the world of firearms, and would like a better understanding of the basics of ammunition, without getting getting lost in the intricacies of manufacturing, or caliber debates.

First a little bit of history.  The modern metallic cartridge wasn’t always how guns operated, and came about only in the mid 19th century.  Prior to that paper cartridges were used, and prior to that powder and ball had to be measured out for every individual shot.  We won’t be going into pre-metallic cartridge firearms today, but given the complicated nature of preparing each shot, a self contained package of everything you need to fire is something to be appreciated.

Whether you call them rounds, cartridges, or shells, all modern ammunition shares a common basic design consisting of just four parts.  Projectile (bullet), Propellant (powder), primer, and case (also sometimes called brass).  These four parts come together to operate easily and efficiently in modern firearms.

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image courtesy of http://ar15.com

Let’s break it down into the job of each part.

Projectile:  The bullet is the part that the rest of the cartridge exists to launch.  It’s a common mistake among non-gunners to refer to the entire cartridge as a bullet, but the bullet is actually only one part of the whole package, much the same as a blade is only part of a knife.  The earliest projectiles fired from a firearm were rocks and arrows, but today’s bullets are usually made of lead.  Lead is ideal for use in bullets as it’s very dense, and as such heavy for its size, and is soft allowing it to deform on impact and spend most of its force on one target rather than piercing through and continuing to hit unintended targets.  Hollow point bullets are made to further enhance that deforming factor.  Some projectiles are not bullets though.  Most notably shotguns fire several smaller projectiles at once known as “shot,” which unlike bullets are spherical rather than domed or conical.  Other materials bullets can be made of include copper, steel, and tungsten, but lead is so far still the ideal mix of weight and softness.  Bullet technology has evolved quite a bit over the last few years and a wide variety of bullet styles are now available, but ultimately most bullets are still just a shaped piece of lead.

Propellant:  Gun Powder is the next major component, and is responsible for doing the work of launching the projectile.  The powder burns rapidly, and in the enclosed space of the case becomes an explosion.  That explosion is directed in one direction behind the bullet forcing the bullet to separate from the rest of the cartridge, and accelerate down the barrel.  Powders also continue to evolve thanks to advances in chemistry allowing for less powder to do the same job, and for powders that burn at different speeds to take advantage of different barrel lengths.  The most significant advancement in gunpowder technology was the advent of “smokeless powder,” which came about in the early 20th century, and replaced the old “black powder,” that had been used for hundreds of years before then.  Smokeless powder obviously didn’t create as much of a smoke cloud, but also burned more cleanly leaving the gun less dirty, but most importantly was much more powerful per volume.  That means that a lot less smokeless powder was needed to produce the same amount of energy than black powder.  This allowed cartridges to become much smaller, while having the same amount of power as older larger cartridges.

http://i695.photobucket.com/albums/vv314/1911canebrake/ammo/DSCF1603-Copy-1.jpg

(Image courtesy of http://ar15.com)  Two .45s.  On the right the .45 log colt, a black powder cartridge, on the left the .45acp a smokeless powder cartridge.  Roughly identical in power.

Whether it’s smokeless, or black powder, all propellant does the same job.  It’s the very fact that this rapid combustion reaction is used to launch a bullet that gives guns the name “firearms,”  Technically a gun isn’t a firearm if it launches a bullet by means other than burning propellant.  For instance airguns, and, lasers, electromagnetic guns aren’t firearms.  In spite of all their advances, over the centuries, guns are still using fire to throw metal.

Primer:  The primer is what gets the powder burning.  The primer is a tiny metal cup filled with a minuscule amount of impact sensitive explosive, and also contains another piece called the “anvil,” to help strike that explosive. 

http://milpas.cc/rifles/ZFiles/Misc/Cartridge%20Primers/image112.JPG

image courtesy of http://milpas.cc

Don’t get scared of the word explosive though.  It’s not as shock sensitive as it may sound, and needs to be struck in a very specific way to set it off.  The primer will be struck by the firing pin, which dents the back of the cup pushing it into the anvil and setting off the explosive between them.  This throws a spark into the inside of the cartridge where the powder is waiting.  Once this happens, the powder begins to burn and the whole firing process begins, all in a fraction of a second.  The Primer is by far the most involved part of the modern cartridge requiring precise machinery and chemistry to manufacture.  Prior to the advances that made these primers possible, metallic cartridges were impossible, and guns had to have an external ignition source such as a piece of flint in order to fire.  It’s such a tiny piece that makes a world of difference. 

In most cartridges the primer is a separate piece from the case which can be removed and replaced, but in rimfire ammunition (such as .22), the primer is actually part of the case.

Case:  Also commonly called “brass” for the metal the case is usually made of, this hollow cylinder is filled with gunpowder, and open on one end to allow a bullet to be seated, and has a much smaller opening on the other to fit a primer.  The case keeps everything together as a single cohesive unit, and is what makes metallic cartridges so convenient.

The case is usually made of brass, which is a malleable metal with a slick surface which can flex to help absorb pressure from firing, and easily be extracted once the round is fired.  However other materials have been used including steel, aluminum, and even plastic to make cases.

Cases can be further broken down into different parts like the primer pocket, mouth, head, and rim, but that’s an article for another day.

The case by its self isn’t strong enough to contain the force of the powder’s explosion.  It needs to be inside a chamber to fire properly.  If a round were set off without being inside of a chamber, the case would simply split open allowing the force of the explosion to escape in all directions without launching the bullet.

Once the round is fired, you’re left with an empty case which needs to be extracted from the gun before another round can be loaded.  Some people save these cases, as they can be rebuilt with powder, primer, and bullet and used again.  This is a money saving hobby known as “reloading.”

When bullet, powder, primer, and case come together a metallic cartridge is born.  The cartridge offers huge advantages over older styles of ammunition in that there is only one step to loading and that is to insert the cartridge into the chamber, and there’s no need to keep up with separate components needed to fire.  Even single shot firearms can fire more quickly thanks to the metallic cartridge, and the dangers of loading mistakes are almost entirely eliminated.

These are the basic principles of all metallic cartridge ammunition.  For over one and a half centuries, this has been the standard technology for all firearms, and while attempts have been made to replace the metallic cartridge, none have succeeded.

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Reblogged from elpatron56  328 notes

cerebralzero:

collegearsenalofficial:

So, beavercreek released the surveillance footage of John Crawford the III.

You CLEARLY see that the entire time he had the pellet rifle, he didn’t once act aggressively with it, and that he was on his phone most of the time. It appears, to me, that he didn’t even know there were cops in the store and was literally blindsided by gunfire.

I wonder if Mike Malloy, who openly advocates calling police the second you see someone carrying a firearm and telling them “Shots fired” and hopes that the person is killed by police, is proud?

Mom’s Demand Action also advocates “SWATTING” open carriers. I wonder if they’re proud?

I wonder if people realize the implications of their suggestions?

This is the direct result of over militarization of police and anti-gun groups in the public.

There is a pretty large chance the person who first called the police and set this whole thing off was anti-gun and they certainly have quite a bit of blood on their hands now.

Antis have had blood on their hands ever since they hung a nice big target on their “gun free zones.”  This is just them being a little more open about how violent they really are.

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Guns for Beginners: Anatomy of a Firearm

Understanding guns is helped along significantly by understanding the basic standard parts that make them up.  Here are the basic parts you can find in any given firearm.

Receiver:  The primary component of a gun.  This is the part that does all the work of housing the trigger, and cycling ammunition into the chamber.  Think of it as the core of the gun, and what is legally considered a gun, while the other parts are simply accessories.  In some guns the receiver comes in more than one part, such as the AR style rifles which have an upper and lower half to the receiver.

Chamber:  Simply put, this is where the round goes in order to fire.  The chamber is the strongest part of the gun, as it must contain the pressure of the exploding powder charge and force it into one direction.  Chambers can be part of the barrel, or a separate piece depending on the type of firearm.  Without a chamber, the pressure of a round would just explode in all directions and accomplish nothing, making for an expensive firecracker.

Barrel:  Most everyone knows what a barrel is.  More specifically the physics of how a barrel works, and how its length plays into the power of the bullet that fires out of it are important.  Think of the barrel as a sort of runway for the bullet.  As the hot gas expands it pushes the bullet in front of it forward down the barrel.  The longer the barrel, the more time this gas has to push the bullet, and the faster it can go.  Additionally with a longer barrel, more of the energy of the explosion is used to push the bullet and less is wasted as recoil, flash, and noise.  Of course the longer a barrel is, the more cumbersome the gun is as well.  Of course there is a limit.  At some point all of the energy of a round is expended and any more barrel length will just create friction, slowing the bullet down.

Rifling:  Part of the barrel of most handguns and rifles (but typically not shotguns).  These grooves cut into the inside of the barrel cause a bullet to spin.  The spinning adds stability to the bullet’s flight and improves range and accuracy.  If a barrel lacks rifling it’s referred to as a “smoothbore.”

Stock/Frame:  This is what the receiver sits in.  The stock may consist of multiple pieces, or just one big piece.  In short it’s what goes around the working parts of the gun to make it something you can hold.  The word stock may also refer to a “buttstock” which is the portion of a long gun that braces against the shoulder.  In the case of handguns, the stock and receiver are usually one unit and are called the “frame,” though there are some pistols which feature the receiver as a separate removable part from the frame.

Magazine:  Unless you’re using a single shot your gun has a magazine.  This is where the rounds not being fired are held.  On a rifle it’s usually a box below the receiver, while on a shotgun it’s a tube below the barrel.  In a handgun it’s often a removable vertical box inside the grip.

Cylinder:  In revolvers, instead of a magazine, you have a cylinder.  The cylinder consists of multiple chambers that rotate into alignment with the barrel.  Since the cylinders are already loaded, there is no need for a loading mechanism.

Bolt:  With the exception of break actions and revolvers, most guns have a bolt of some sort.  The bolt does a few things.  First it contains the firing pin, second it pushes a round into the chamber, third it locks the chamber shut and holds the round in the chamber while firing, and lastly it usually grips the back of the case somehow so that it can also extract the round from the chamber after firing.  In the case of most semi automatic pistols, this purpose is served by the slide. 

Firing Pin:  A small, thin, metal rod that strikes the primer of a round causing it to fire.  Some firing pins are fired by a spring, others are fired by a hammer which strikes the back of the pin.  This varies from gun to gun, but all firearms that fire metallic cartridges use a firing pin.

There are more specific parts to particular types of actions, but these basic components are what make a firearm run, and knowing what theya re and where they are in your gun will give you a lot more understanding of the piece of engineering in your hands.

Comments
Reblogged from elpatron56  121 notes
cerebralzero:

johnnysixpack:

Gun control advocate, Alison A. Martin, goes full retard.

I feel like this might be a good tactic to work into debates in the future. Throw out some Nazi quotes, watch the gun control advocates agree with them(since there views are consistent with that sort of thing), proceed to allow your sides to fly into orbit never to be seen again.

HA!

cerebralzero:

johnnysixpack:

Gun control advocate, Alison A. Martin, goes full retard.

I feel like this might be a good tactic to work into debates in the future. Throw out some Nazi quotes, watch the gun control advocates agree with them(since there views are consistent with that sort of thing), proceed to allow your sides to fly into orbit never to be seen again.

HA!

Comments
Reblogged from peashooter85  131 notes

peashooter85:

The Velodog Revolver,

A creation of the French pistol maker Charles Francois Galland in the late 19th century, the Velodog was a small pocket revolver popular in France and Belgium in the late 19th and early 20th century.  While there were many makers of Velodog revolvers in Europe at the time, most share common characteristics.  First, they were small five or six shot double action revolvers, often hammerless and lacking a trigger guard.  Instead of a trigger guard, for the safety most Velodogs had a folding trigger, which also made the pistol more compact for carrying.  Secondly, most Velodogs were of small caliber.  At first they were produced in a caliber called 5.75 Velodog, a 5.5mm (.22 caliber) jacket cartridge similar to the .22 magnum today.  Later Velodogs were produced in other small calibers such a .22 long rifle and .25 ACP.

The purpose of the velodog was very specific, for bicyclers to defend themselves against dog attacks. The name “velodog” is a portmanteau of the words “velocipede”, an early type of bicycle (pictured above), and “dog”.  While this may seem laughable today, remember that at the time, bicycles were crude, slow vehicles and that 19th century Paris was infested with thousands of dangerous, rabid dogs.  For those seeking a more human solution, 5.75 Velodog cartridges were produced loaded with cayenne pepper.

No proper dandy dare stride upon his velocipede without one.

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Thanks Everyone

The Gun Geek Frag Blog is now up to 100 followers.  I’m glad so many people enjoy my little rants and articles about all sorts of guns.

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Support the Hell out of this

http://www.nraila.org/legislation/federal-legislation/2014/9/usa-freedom-act-would-curtail-government-surveillance-programs.aspx

Reblog, repost, tweet, tell your friends, write your congressman.  This is something both libs and conservatives can get behind.  There’s no reason not to support this.

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Reblogged from peashooter85  176 notes
peashooter85:

The Delhaxhe Knuckleduster Revolver,
While the most famous, the Apache pinfire revolver was not the first knuckleduster revolver design.  There were several that came before, and many more that were made after.  The Delhaxhe was a design that was produced in 1870 six years before the introduction of the Apache.  Made in Belgium, the Delhaxhe fired an 11mm pinfire cartridge.  The Delhaxhe was different from the Apache in two major ways.  First, the Apache had a folding grip/knuckleduster whereas the Delhaxhe was solid frame and grip.  Finally the Apache had a forward pointing blade whereas the Delhaxhe’s blade was located under the grip.  To make use of the blade, the user either had to turn the pistol upside down, creating a formidable knife and knuckleduster combo, or the user could simple swing the blade in a hammerfist style fashion.  

It’s weird and I love it. 

peashooter85:

The Delhaxhe Knuckleduster Revolver,

While the most famous, the Apache pinfire revolver was not the first knuckleduster revolver design.  There were several that came before, and many more that were made after.  The Delhaxhe was a design that was produced in 1870 six years before the introduction of the Apache.  Made in Belgium, the Delhaxhe fired an 11mm pinfire cartridge.  The Delhaxhe was different from the Apache in two major ways.  First, the Apache had a folding grip/knuckleduster whereas the Delhaxhe was solid frame and grip.  Finally the Apache had a forward pointing blade whereas the Delhaxhe’s blade was located under the grip.  To make use of the blade, the user either had to turn the pistol upside down, creating a formidable knife and knuckleduster combo, or the user could simple swing the blade in a hammerfist style fashion.  

It’s weird and I love it. 

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