Guns 101

OK, so what are those “mechanical attachments” that are part of a gun? Well, let’s break it down into some basic pieces:

Gun Components

In 99.9% of all cases, all guns include the following parts: muzzle, breach, hammer and trigger. These components often determine how a firearm operates and how it is classified.

Muzzle: The Business End of a Gun

Muzzle = Front. Or, more specifically, the muzzle is the opening on the front of a firearm. This is where the projectile comes out of. Click on the examples below for more detail.

The muzzle is the open end of the front of a gunMuzzle of a Pistol

The Breech

Simply, the breech is the back. With early firearms, the technology limited how guns were loaded. For centuries, guns could only be loaded through the muzzle and they were known as “muzzle-loading” guns. Later, as technology improved, guns could be loaded through the breach and were referred to as “breech-loading”. Click below to see some examples of gun breeches:

The BreachThe Breach

The Hammer

The hammer is the part of the firearm that makes contact with the bullet primer to ignite the powder and propel the bullet out of the muzzle (read more about bullet cartridges). For most handguns and some rifles, the hammer is visible on the outside of the firearm. However, for most rifles and shotguns and some pistols, the hammer is internal.

With some guns, the hammer doesn’t even contact the primer directly at all. In those cases, a firing pin is used. The firing pin is struck by the hammer driving it forward into the bullet’s primer to fire the round.

A Pistol HammerA Pistol Hammer

The Trigger

The trigger is the part of a firearm that files the round. On certain guns, like single action revolvers, the hammer has to be “cocked” – or pulled back into position – before the trigger can be pulled. In those cases, the pull of the trigger releases the hammer to fire the round. With most other guns, the trigger pull is considered double action in that pulling the trigger both cocks the hammer and releases it thereby firing the weapon..

A Pistol TriggerA Pistol Trigger

28 thoughts on “Guns 101

  1. Donna Accettola on said:

    Trying to teach myself with your help.

  2. Tanvir Ahmed on said:

    Okay . What is the name of the part of guns which is alike binocular ?
    Example ; Springfield M1903 .
    Anyone , expert about guns please contact me . Here is my email ;

  3. LaTasha Rudley on said:

    Thank you for this.

  4. Chris on said:

    Good description

    • Ryan on said:

      It should include a complete composition of all of the parts of the gun, and include the different kinds of ammunition, and the composition of multiple kinds of guns, like shotguns, sniper rifles, assault rifles, and fully automatic machine guns

      • A Gun Guy on said:

        Hi Ryan. Thank you for your comment. This page is intended to be a very basic starting guide for how a gun works and it’s most basic components. We are compiling a catalog of information on various types of fierarms and ammunition that we hope to add to the website very soon.

        • Yankee2 on said:

          Well put, gun guy!

  5. favoursledge on said:


  6. Mohak Sahu on said:

    I want to know more basic knowledge about guns.

  7. Kerri on said:

    Im a petite female (5.1ft & 100 lbs soaking wet). Im also a farmer and this year we decided to get deer permits for crop damage. My husband has a .243 that he uses to shoot at the deer but due to the bang I cant be anywhere near when its fired. I not only have extremely sensitive ears but I have a issue with getting scared or startled easily. I would like to be able to shoot but all I have is a .22 which is not appropriate for my goal. Is there something out there powerful enough to kill a deer but yet quiet enough it wouldnt bother me? Any suggestions would be greatly appreciated, thanks!

    • Austin on said:

      Welcome to the club, Kerri! I also don’t like unexpected loud noises, and guns also made me nervous. I personally have invested in a compound bow, which I absolutely love. That may not be practical for your specific situation, and if it isn’t, then you may want to investigate into an air gun that is powerful to shoot a deer. Another option is a .22 Magnum.
      Something else you may want to look at is an Air gun. Air guns are very quiet, and there are multiple people who have killed animals bigger than deer with them. For example, TV personality Eva Shockey killed a huge wild boar in Texas with one shot from a .25-caliber Benjamin Marauder air rifle.
      I’m also no big expert on guns by a long shot, but those are a few suggestions :)

  8. Jim on said:

    Can someone explain the difference between a 38 special and a 38 special +P? I cannot seem to figure it out.

    • A Gun Guy on said:

      Hi Jim. +P just means that the load generates pressure exceeding the SAAMI specified maximum for that round. That means that it’s a “hotter” load than the standard .38 Special meaning increased velocity and stopping power. It is not recommended to use +P rounds in older firearms as they are not built to withstand that extra pressure. But, newer models (last 25 years or so) can handle the +P rounds. Consult your gun manufacturer’s recommendations, though, before using it.

    • Mike on said:

      On any ammo classified +p all that means is that the pressure inside the cartridge is more than normal and bullet velocity is greater. Some firearms should not use +p ammo. But most modern firearms can. Check your owners manual.

  9. Therese on said:

    What type of gun would be good for a woman? I have zero to no experience except firing a .9 mm at the range that has too much kick for me. Im looking for a full size gun AND one for conceal carry. Im taking a gun safety course and cc class soon.

    • A Gun Guy on said:

      Hi Therese. Someone I know just recently spoke to a female police officer about this very subject. She and many other woman I’ve spoken to often recommend a .380 caliber or what is also often referred to as a “short nine”. The .380 round is the same diameter as a 9mm but is shorter and has less powder and therefore less recoil. It is one of the most common concealed carry pistols available today. There are many different makes and models such as Beretta’s Pico ( I’d start there and see if you can rent one at a local gun range to get a feel for it yourself.

        • Cody on said:

          Don’t be fooled by the idea that a woman has to use a smaller caliber gun. Although there is less powder in a .380 than a 9mm the .380 pistol is often much smaller and lighter than its 9mm counterparts. This results in snappier recoil in many cases. the best thing to do is go to a range that rents guns and try them out. Every body is different and as they say “your mileage may vary”.

  10. ricki on said:

    First of all I want to say thank you for this website. It’s been pretty helpful in gaining more knowledge on guns & ammo! My question is, I’m looking to buy a gun for concealed use. I would prefer a revolver (I’ve tried 9mm SA a few times and didn’t care for them), but I’m not sure which would be better for me. A few guns I had in mind include the S&W bodyguard 38, .38 Special S&W or .357 S&W. I’m still new to guns (I did take a safety course, I’m just don’t know that much about the guns themself) so I’m not sure which would be better. I do understand that a .357 can use .38 and .357 ammo, but is also more powerful than a .38. Any suggestions?

    • tony on said:

      nothing wrong with a revolver i would go with 357 because one is the ammo you might find different stuff on sale next you wont see much difference in recoil and really a revolver in my opinion is more dependable just not enough ammo for me, anything is better than nothing

  11. Jim on said:

    What is a Picatinny rail?

    • A Gun Guy on said:

      Hi Jim. A Picatinny rail is a system integrated into a firearm to allow for easily adding and removing attachments like a site, or laser or flashlght, etc. Picatinny rails are either integrated into the firearm by the manufacturer or can be added to some firearms as a modification.

  12. prapunch on said:

    If someone wants to learn how to manufacture guns, what should they do?

    • A Gun Guy on said:

      Get and apprenticeship with a gunsmith

  13. gunforatonguexo on said:

    Breech** lol

  14. Mark on said:

    What does “ACP” mean in Colt 1911 .45 cal ACP?

    • A Gun Guy on said:

      ACP stands for Automatic Colt Pistol. It’s used most commonly to describe the .45 and .380 calibers used in semi-automatic handguns. The .45 ACP was invented by John Browning when he first developed the 1911 pistol as a replacement for the standard issue .38 caliber revolver carried by U.S. servicemen. Up until then, most handguns were revolvers but the 1911 was semi-auto. I believe that it was given the designation ACP to separate it from other .45 caliber rounds that were often used in rifles prior to the introduction of the 1911 pistol.

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