A1, A2, A3 etc… Refers to military designations or alterations of various firearms including M16 & M4.
AR – Means ArmaLite right? There is some debate as to the meaning of AR as the original ArmaLite company designed the AR15 rifle, Colt later has a CAR 15, which was based on the original Eugene Stoner ArmaLite design, however the CAR meant Colt Automatic Rifle.
AWB – Assault Weapons Ban. An infringement on your 2nd Amendment rights is the classifying of what an assault weapon is typically by legislative body (government).
BBL – Barrel.
BCG – Bolt Carrier Group
BDC – Bullet Drop Compensator
BRD – Black Rifle Disease
BUIS – Back Up Iron Sight
CAR – Carbine. A carbine is a medium barrel length rifle, typically with a 16″ long barrel.
Compliant – Typically refers to Ar15′s or parts and accessories which adhere to various infringements, bans or restrictions; such as “California Compliant”.
CQB – Close Quarters Battle.
DC – Dust Cover
DCH – Detachable Carry Handle
DD – Daniel Defense
DD – Destructive Device
DI – Direct Impingement firearm operating system where the action is cycled directly by the cartridge gasses. Most famously used in the AR15 and M16 series of rifles.
DIAS – Drop-In Auto Sear
DIY – Do It Yourself
DPMS – Defense Procurement Manufacturing Services – builder of AR-15 rifles and supplier of parts and accessories
DSA – D.S. Arms
EBR – Evil Black Rifle
ETA – Estimated Time of Arrival
FA – Forward Assist
FA – Full Auto
FAQ – Frequently Asked Questions
FCG – Fire Control Group (the hammer, trigger, disconect, springs and selector)
FDE – Flat Dark Earth (a tan-brown color making inroads as a replacement for black in weapon coloring)
FF – Free Float/Floated/Floating
FFL – Federal Firearms License/Licensee – a license that permits one to sell and/or transfer guns in interstate commerce.
FH – Flash Hider
FMJ – Full Metal Jacket – a bullet that is encased in a metal jacket.
FMJBT – Full Metal Jacket Boat Tail
FN – Fabrique Nationale
FOIA – Freedom Of Information Act
FP – Firing Pin
FS – Flash Suppressor
FSB – Front Sight Base
FSP – Front Sight Post
FST – Front Sight Tower
FTE – Fail To Eject/Extract
FTEj – Fail To Eject
FTEx – Fail To Extract
FTF – Fail To Feed
LPK – Lower Parts Kits
FSB – Front Sight Base, sometimes called Front Sight Post.
GCA – Gun Control Act of 1968
HBAR – Heavy Barrel
HG – Handguard
HP – Hollow Point (a bullet with a hollow cavity at the tip)
HTS – Hammer, Trigger, Sear (parts of the FCG)
ID – Inside Diameter
ID – Involuntary Discharge (an unintentional discharge of a weapon resulting from a physical reaction beyond the shooter’s instant control – e.g. a muscle spasm)
IPSC – International Practical Shooting Confederation (Also See USPSA)
JHP – Jacketed Hollow Point – a bullet that is jacketed in metal, but with a hollow cavity at the tip
JSP – Jacketed Soft Point – a bullet that is jacketed in metal, but with exposed lead at the tip.
LOP – Length Of Pull – the distance from the face of the trigger to the end of the buttstock.
LPK – Lower Parts Kit
LW – Lightweight
M16 – The original full-auto military version of the AR-15 rifle.
M4 – A 14.5″ barrel carbine version of the M16A2.
MAP – Minimum Advertised Price (A price below which retailers are prohibited from advertising a product. Not all manufacturers/distributors enforce MAP policies, and even when they do, retailers are not legally prohibited from selling below MAP.)
Mil Spec – Military Specification. A United States defense minimum standard, often called a military standard, “MIL-STD”, is used to help achieve standardization objectives. Mil Spec will define shape, size, metallurgy and treatments of a firearm and firearm components. Also see TDP.
MOA – Minute Of Angle – a measure of angular displacement equal to 1/60 of one degree, usually used when discussing group sizes – 1 MOA is roughly 1″ at 100 yds.
MP – proof mark that indicates Magnetic particle inspection and Proof load firing has been performed on a barrel. Magnetic Particle [inspection/testing] (Magnetic particle inspection is a non-destructive steel inspection method used to ensure that a barrel, for example, is free from metallurgical defects such as cracks.
MRF – Modular Rail Forend (a rail adapter system made by Troy Industries)
MSRP – Manufacturer’s Suggested Retail Price
ND – Negligent Discharge (an unintentional discharge of a weapon that reasonably should have been forseen and prevented)
NFA – National Firearms Act (of 1934 – the law governing machine guns, sawed off shotguns, short barreled weapons, suppressors, etc.)
NICS – National Instant Criminal Background Check System (the system established as part of the Brady Act to check for disqualifying information that would prevent legal transfer of a firearm to a person)
NM – National Match – Sometimes used to describe the 1specified quality of an item. However refers to the National Matches sponsored by the Civilian Marksmanship program.
NSN – National Stock Number – a unique number assigned to each item in the Federal Supply Cataloging System, including parts and accessories for military weapons.
NVD – Night Vision Device
OAL – Overall Length
OD – Olive Drab. Sometimes called ODG for Olive Drag Green or Army Green.
OD – Outside Diameter
OTM – Open Tip Match – a type of hollow point bullet designed for long range accuracy.
PAFS – Permanently Attached Flash Suppressor – generally permanantly attached in order to bring a barrel’s overall length to 16″ and thus avoid the legal restrictions on SBRs.
PDW – Personal Defense Weapon – a compact weapon designed primarily for defensive rather than offensive operations.
POA – Point Of Aim
POI – Point Of Impact
Post ban – Typically referring to AR15′s which adhere to the 1994 Clinton Assault Weapon Ban which has since expired.
Pre ban – Typically referring to AR15′s or parts and components without restriction.
PRS – Precision Rifle/Sniper – a precision stock made by Magpul, adjustable for height and LOP.
QCB – Quick Change Barrel.
QD – Quick Detach.
RAS – Rail Adapter System.
RDIAS – Registered Drop-In Auto Sear
RIS – Rail Interface System
RLL – Registered Lightning Link (a LL legally registered under the NFA. By itself considered to be a machine gun under the NFA)
ROF – Rate Of Fire
SAAMI – Sporting Arms and Ammunition Manufacturers’ Institute – an association of manufacturers of sporting firearms, ammunition, and components. Often used to distinguish between the sporting .223 chamber [the SAAMI chamber] and the military 5.56 mm chamber.
SAW – Squad Automatic Weapon
SBR – Short-Barreled Rifle (a rifle whose barrel is less than 16″ long as defined by the NFA)
SD – Shell Deflector
SMG – Sub Machine Gun
SP – Soft Point – a bullet whose lead tip is exposed rather than jacketed in a harder metal.
SPC – Special Purpose Cartridge as in “6.8 mm SPC”.
SPR – Special Purpose Rifle – precision rifle with 18″ free floating match barrel upper.
SS – Stainless Steel
TDP – Technical Data Package – the collection of drawings, engineering notes, etc. that describe in detail the design and construction of an item.
UBR – Utility/Battle Rifle (a general purpose adjustable stock made by Magpul, with a fixed cheekweld. Successor to the M93B.)
UD – Unintentional Discharge (a weapon discharge made without deliberate or conscious intent, including accidental, involuntary and negligent discharges)
USGI – United States Government Issue – Usually is used as a reference to magazines.
VFG – Vertical Fore/Forward/Front Grip