The AR platform is the most popular airsoft platform with the widest variety of upgrades and accessories. This illustrated guide reviews the different AR-type rifles available from a historical perspective. Some variants are not seen commonly in airsoft, e.g., AR-18, Colt Commando 9mm, HK416C, and were not included. The airsoft gun pictures below the description are provided to help you customize your gun to look like a particular variant.

AR-15 (1959)

AR is short for the Armalite-15 (AR-15), an assault rifle developed by the Armalite Corporation in the 1950's. This was a prototype of the M-16 rifle below.

M-16 (1962)
Caliber: 5.56mm
Barrel: 20"
Handguard: Triangular
Stock: Fixed
Magazine: 20 round box


M-16 was the official military designation for the AR-15. The rifle was mass-produced by the Colt Firearms and saw extensive action in the Vietnam Conflict. The initial M-16 has a duckbill or three-prong flash hider and used a 20-round box magazine.

M16A1 (1966)
Caliber: 5.56mm
Barrel: 20"
Handguard: Triangular
Stock: Fixed
Magazine: 20 round box


The M16A1 was an improvement of the M16 that addressed malfunctions in the original M16. The major change was the addition of a plunger-type forward bolt assist on the right side of the receiver. Later versions of the M16A1 had the birdcage flash hider.

Air gun Trigger Gun barrel Gun accessory Machine gun

M16A1
XM177/CAR-15/Commando (1967)
Caliber: 5.56mm
Barrel: 10" or 11.5"
Handguard: Round, ribbed
Stock: Collapsible
Magazine: 20 round box


A shorter version of the M16 was developed for the close-quarter battles in the Vietnam Conflict. The XM177 was developed as a carbine-length variant of the M16 with the same receiver but a barrel half the length of a M16. Other external changes included a round ribbed handguard, collapsible stock and a longer flash hider. The XM177E1 (alternatively named the CAR-15 or Commando) was modified to have an 11.5" barrel. All variants used the 20-round magazine.

Air gun Machine gun Trigger Gun barrel Gun accessory

XM177 - note longer flash hider. This replica has a longer magazine.

M16A2 / M16A3 (1982)
Caliber: 5.56mm
Barrel: 20"
Handguard: Round, ribbed
Stock: Fixed
Magazine: 30 round NATO STANAG


The M16A1 underwent a major revision in the early 1980's to become the M16A2. The major external changes were a change from a triangular to a round handguard and a re-designed pistol grip and buttstock. A new adjustable rear-sight and revised birdcage were other changes. The fully automatic fire feature was replaced with a three-round burst feature. The M16A3 variant restored the full-auto feature. The M16A2 and later variants use the standard 30-round NATO STANAG magazine.

Air gun Trigger Gun barrel Machine gun Gun accessory

M16A2 with round handguard

M733 (1987)
Caliber: 5.56mm
Barrel: 10.5" or 11.5"
Handguard: Round, ribbed
Stock: Collapsible
Magazine: 30 round NATO STANAG


The M733 is a modernized version of the CAR-15 developed by Colt with an 11.5" barrel. The Colt Commando is identical except for a 10.5" barrel. It uses some of the enhancements seen in the M16A2 including the new handguard and flash hider.

Air gun Trigger Gun barrel Gun accessory Recreation

M733

M4 (1991) / M4A1 (1996)
Caliber: 5.56mm
Barrel: 14.5"
Handguard: Round, ribbed
Stock: Collapsible
Magazine: 30 round NATO STANAG


The M4 was a new carbine to replace the Colt Commando. It was based off the M16A2 and had the 3-round burst feature. The US Army updated the design to be the M4A1 with the full-auto capability restored. Newer M4A1s have an ambidextrous selector switch. The M4A1 began replacing the M16 as the standard US service rifle and has been produced by Colt, Remington and FN.

Air gun Trigger Gun barrel Gun accessory Recreation

M4A1

SR-25 / Mark 11 (1992) / M110 SASS (2005)
Caliber: 7.62mm
Barrel: 20"
Handguard: Rail Interface System (KAC)
Stock: Fixed
Magazine: 20 round box


The SR-25 (or Mark 11) was designed as a sniper rifle for the US Marines and made by Knight's Armament Company (KAC). The SR-25 is chambered in 7.62x51mm with a 20" barrel and fixed buttstock. The SR-25 is semi-automatic fire only and a suppressor can be easily added. The M110 SASS (Semi-automatic Sniper System) replaced the SR-25 and has a different buttstock, rail and scope ring system.

Air gun Trigger Machine gun Gun barrel Gun accessory

SR-25 (Mk11) with scope

SOPMOD Block 1 and Block 2 (1993)
Caliber: 5.56mm
Barrel: 14.5"
Handguard: Rail Interface System
Stock: Collapsible
Magazine: 30 round NATO STANAG


SOPMOD (Special Operations Peculiar Modifications) is a modification kit for the M4A1 to meet requirements of the US Special Operations Command (SOCOM).

Block 1: Includes advanced optics, e.g., ACOG or ELCAN, Knight's Armament rail system, vertical foregrip, and suppressor.

Block 2: Like block 1 except the rail system is from Daniel Defense. Uses newer advanced optics, such as an ELCAN or Eotech.

Air gun Trigger Line Gun barrel Gun accessory

SOPMOD Block 2

Mark 18 (1994)
Caliber: 5.56mm
Barrel: 10.5"
Handguard: Rail Interface System (DD)
Stock: Collapsible or Crane
Magazine: 30 round NATO STANAG


The Mark 18 was originally a modification of the M16A1 with a shorter (10.5") barrel and new upper receiver, called the Close Quarter Battle Receiver (CQBR). Later Daniel Defense (DD) would manufacture the entire carbine. The US Navy developed the Mark 18 in Mod 0 and later Mod1 configurations. The Mod 0 and Mod 1 are essentially the accessories in the SOPMOD Block 1 and Block 2 kits.

Air gun Trigger Machine gun Gun barrel Gun accessory

Mark 18 Mod 1

M16A4 (1998)
Caliber: 5.56mm
Barrel: 20"
Handguard: Rail Interface System
Stock: Fixed
Magazine: 30 round NATO STANAG


The M16A4 is the latest generation of M16 rifles and is used by the US Marines.

It has a detachable carry handle as well as a rail system instead of the traditional handguard. The M16A4 is manufactured by FN and trademarked as such on the lower receiver.

Font Rectangle Auto part Metal Fashion accessory

M16A4 with rail interface system and scope

Mark 12 SPR (2000)
Caliber: 5.56mm
Barrel: 16"
Handguard: Free-float tube or Rail Interface System
Stock: Fixed
Magazine: 30 round NATO STANAG or 20 round box


The Mark 12 Special Purpose Rifle (SPR) is a designated marksman rifle designed by the US Navy for the Navy SEALs. External modifications include a 16" barrel, a free-floating handguard and a bipod. Unlike the Mark 11, the Mark 12 retains fully automatic function. Early versions (Mod 0) used a free-float tube for the handguard but later versions (Mod 1) used a rail interface system.

Air gun Trigger Line Gun accessory Gun barrel

Mark 12 Mod 0

HK416 (2004)
Caliber: 5.56mm
Barrel: 10.5", 14.5", 16.5", 20"
Handguard: Rail Interface System
Stock: Collapsible (HK)
Magazine: 30 round NATO STANAG


The Heckler & Koch HK416 was designed to be a more reliable version of the M4A1. A new upper receiver was matched to the existing lower receiver. The HK416 has a different stock and handgrip and added a free-floating rail system. Like all modern ARs it uses a 30-round NATO STANAG magazine and has an ambidextrous selector switch.

Air gun Trigger Gun barrel Machine gun Gun accessory

HK416

HK417 (2005) / G28 (2012)
Caliber: 7.62mm
Barrel: 13", 16.5" or 20"
Handguard: Rail Interface System
Stock: Collapsible (HK)
Magazine: 20 round transparent polymer


This is an HK416 chambered in 7.62x51mm. It has a 20-round transparent magazine like the G36 magazine. The G28 is a semi-automatic only, 16.5" barrel version used as a DMR by the German army.

Air gun Trigger Gun barrel Gun accessory Composite material

HK417

HK416 DEVGRU (2009)
Caliber: 5.56mm
Barrel: 10.5" or 14.5"
Handguard: Rail Interface System
Stock: Magpul CTR
Magazine: 30 round NATO STANAG


The US Navy Special Warfare Development Group (also known as DEVGRU) modified the HK416 for use with the Navy Seals. The main addition is an AAC suppressor and the stock may be changed to a Magpul CTR type stock. The gun has an advanced sight such as an Eotech or ELCAN. The guns are usually painted in a camouflage scheme.

Air gun Trigger Gun barrel Machine gun Gun accessory

HK416 DEVGRU. This replica has the longer barrel and Crane stock.

M27 IAR (2010)
Caliber: 5.56mm
Barrel: 16.5"
Handguard: Rail Interface System
Stock: Collapsible (HK)
Magazine: 30 round NATO STANAG


The M27 Infantry Automatic Rifle is a variant of the HK416 that has been modified as a light machine gun. The M27 IAR is in service with the US Marines. Although designated a support weapon, it uses a 30-round NATO STANAG magazine.

Air gun Trigger Machine gun Gun barrel Gun accessory

M27 IAR

M203
Caliber: 40mm
Barrel: 12"
Handguard: Round, ribbed


The M203 is a single-shot under-barrel 40mm grenade launcher. The M203A1 is compatible with the M16A1 and M16A2 while the M203A2 is compatible with M4 rifles. The M16 variants have a metal shroud over the handguard while the M4 variants are attached to the lower rail. A M16A1/M203 rifle was depicted in the movie "Scarface".

Trigger Air gun Gun accessory Metal Gun barrel

M16A1 with M203 grenade launcher
References:

Kyle, Chris. American Gun. A History of the U.S. in 10 Firearms. New York: HarperCollins. 2013.

Owen, Mark. No Easy Day. The Autobiography of a Navy Seal. New York: Dutton. 2012.

https://www.ammoland.com/2016/04/ar-15-rifle-historical-time-line/#axzz4resmfH7x

https://www.americanrifleman.org/articles/2012/6/22/us-m16/

http://www.smallarmsreview.com/display.article.cfm?idarticles=1381

http://www.heckler-koch.com/en/products/military/assault-rifles.html

https://fnamerica.com/products/rifles/fn-m16a4/

http://www.colt.com/Catalog/Military/Products/Colt-M4-Carbine#100843-overview