Ammo Encyclopedia

In the movie, Full Metal Jacket, a drill sergeant is yelling at a soldier and says “What is your major malfunction?” This line has been popularized online as a meme. In the context of the film, it means that he wants to know what’s wrong with the recruit because he is not doing well in boot camp training.

But we are not talking about the film. We are talking about a type of ammunition. Full metal jacket ammunition has a soft lead core that is coated on top with a harder metal. It can also be called ball ammo.

FMJ ammo is great for plinking and target shooting but not for self defense or hunting. FMJ ammo will go through your target and endanger people behind it. Always use hollow points for self defense. Here is our in depth article on Full Metal Jacket ammo.

Rimfire ammo is a type of primer-ignited metallic firearm cartridge whose primer is contained in the cartridge’s rim. The cartridge fires when the firing pin strikes the primer. This type of ammo is not reloadable. Rimfire ammo is usually low-pressure and cheaper hence it’s popularity in sport shooting, plinking, and small-game hunting. Here is our in depth article about rimfire ammo.

Remanufactured ammo is processed using specialized equipment to reload brass casings that were once fired. This ammo has a cost-efficient price point and is still of decent quality that many people trust. Here is our in depth article about remanufactured ammo.

Caseless ammo is a small arms ammunition that attempts to reduce the cost and weight of ammo and simplify its operation by eliminating the cartridge case that usually holds the propellant, primer, and projectile together. The lack of metal casing decreases the weight, allows for smaller cartridges and higher cyclic rates. However, the sealing of the chamber and heat sensitivity over sustained gunfire is an issue of concern. Here is our in depth article about caseless ammo.

You can easily identify centerfire ammo because the primer is in the center of the cartridge. This ammo is high-pressure and high-velocity. It is used by police forces as well as civilians for defensive purposes. This ammo can be reloaded and is used in shotguns, handguns, and rifles. Larger loads of centerfire ammo can produce a recoil that is unmanageable for some shooters. Here is our in depth article about centerfire ammo.

Non-Typical ammo is a trademark of Federal Ammunition. It is a set of 13 different calibers and loads specifically made for deer hunting. According to Federal, non-typical ammo, “uses an optimized soft-point bullet with a concentric jacket to provide tag-punching accuracy and consistent, lethal wound channels on any whitetail, mule deer or other species”. Here is our in depth article about non-typical ammo.

Total Metal Jacket (TMJ) ammo is specifically designed for the reduction of lead particles released in the air. A thin jacket of ductile metal, usually copper, is electroplated on the bullets. This jacket fully covers the bullet for protection against corrosion, making it safe for indoor use and for healthier shooters.

XTP Ammo is a trademark of Hornady. The eXtreme Terminal Performance (XTP) ammo is a controlled expansion bullet designed for hunting, law enforcement, and self-defense. It has accuracy, deep penetration, and expansion properties.

Brass Enclosed Base (BEB) ammo meets indoor shooters’ needs, being the reverse of a full metal jacket. The front part of BEB bullets have exposed lead, and since the lead is away from the ignition source, lead particles in the air are reduced. Though rarely an issue, their downside is the potential to jam in semiautomatic weapons as a result of the indentation on the bullet’s nose where lead is exposed. Here is our in depth article on BEB ammo.

Pointed Soft Point (PSP) ammo is one of the most common metal jacket bullets that offer greater penetration and more expansion than a hollow point. It has a lead core wrapped in a copper casing and a pointed tip for accuracy. PSP ammo is intended to expand upon hitting its target. They are ideal for hunting large game because they will expand on impact to ensure a kill.

Gas check ammo is a copper gasket type component made to fit on the bullet’s base to inhibit lead buildup in the barrel and improve its accuracy. They are used where high-pressure cartridges (faster than 1400fps) use non-jacketed bullets. The bullet’s base shank that accepts the gas check is rebated, and attachment can be done without altering the bullet’s maximum diameter.

A short barrel rifle (SBR) is a shoulder-fired firearm with a buttstock and a barrel of fewer than 16 inches. The SBR requires that you fill out special ATF Form 1 paperwork and pay a $200 tax. SBR ammo is optimized to reach full speed and energy when fired through a short barrel.

Bonded ammunition is jacketed ammo that maintains its jacket and core intact even after penetrating the target. The core and the jacket can be bonded through a soldering process by melting lead inside the copper jacket. Another way to make bonded ammo is via an electrochemical process where the jacket is applied as an exterior plating on a formed core. Its primary purpose is large-game hunting as it is reliable when deep penetration is needed.

Lead Round Nose (LRN) ammo is purely made of lead and with a rounded nose that looks like a half-sphere. The ammo easily jams and leaves more powder particles in the barrel. This negatively affects downrange accuracy but can be corrected by cleaning the barrel. The ammo keeps its basic shape even when the soft metal expands, delivering a balanced penetration and expansion ideal for hunting.

Reloaded ammo has already been fired once and then reloaded for a second use. Reloading of ammo is done by shooting enthusiasts instead of buying commercial ammunition. Reloading is typically done to save money but some people make their own ammo to increase accuracy. It is good to note that the cartridge gets weaker and prone to failure with each firing.

OTM stands for open tip match ammo, one that is a hollow-point, and is used as target shooting ammo. Its rounds are more accurate compared to the Full Metal Jacket ammo, and hence are a preference for shooters who require extreme accuracy in competitions.

Snap cap ammo is an accessory device for firearms shaped to replicate a live round/cartridge/shotshell but without the ammunition components, which are the gunpowder, primer, propellant, and projectile/bullet. They are used in guns to absorb moisture, to keep bores lubricated, and to avoid damage to the firing pin. There are some snap caps whose false primer is spring-dampened but those are more expensive.

Snaps caps are completely passive and produce no sound. Their only purpose is to prevent firing pin/striker damage and aid in tactical reloading practice and dry firing.

TMJ stands for Total Metal Jacket where TMJ ammo is fully covered in copper plating. These are mainly used in Match shooting due to their accuracy. TMJ helps reduce lead contamination amounts, especially in indoor ranges. This ammo is not recommended for ported firearms, since as the bullet leaves the barrel, its casing might get sheared off. Here is our in depth article on TMJ ammo.