A3 vs A4 AR upper
- Thread starter major519
- Start date
A1-A2 has a raised handle which includes the rear sight (considered very old school, because using optics on these is not practical)
flat-top (has many different names) is the most common design because you can scope it easilly and if you want you can add a removable A2 handle to make it like the A2. So this is the best setup for flexibility.
flat-top (has many different names) is the most common design because you can scope it easilly and if you want you can add a removable A2 handle to make it like the A2. So this is the best setup for flexibility.
Last edited:
mebiuspower
CGN Ultra frequent flyer
- Location
- Morontario
A4 has M4 feedramps, A3 does not.
Glock4ever
CGN Ultra frequent flyer
- Location
- Edmonton, AB
A3/A4 has no meaningful difference for civilian AR-15's. I wish I still had the link which indicated the differences but a quick summary from the top of my head (if it is a bit wrong I apologize now):
M16 - No forward assist, same fixed sights as listed on A1. Full auto.
M16A1 - Old carry handle with no adjustment for elevation on the rear sight. These were great front sight post for elevation and rear sight for windage. These were full auto. Fwd Assist was added to this model with some other minor changes, I believe they also added a hole in the buttstock for the cleaning kit.
M16A2 - New carry handle with adjustment for elevation/windage and 3 round burst added/Full Auto gone.
M16A3 - Flat top. Full Auto.
M16A4 - Flat top. 3 round burst.
There were other changes between the various models but quite minor. I also might have mixed up the 3 rd burst between the A3 and A4 as I misremember if the US military decided it was better to have full auto or not. As for A3/A4 have M4 feedramps - that is incorrect. Only M4's have M4 feedramps (in military rifles) and I believe the M4 is only at the A2 for improvements.
M16 - No forward assist, same fixed sights as listed on A1. Full auto.
M16A1 - Old carry handle with no adjustment for elevation on the rear sight. These were great front sight post for elevation and rear sight for windage. These were full auto. Fwd Assist was added to this model with some other minor changes, I believe they also added a hole in the buttstock for the cleaning kit.
M16A2 - New carry handle with adjustment for elevation/windage and 3 round burst added/Full Auto gone.
M16A3 - Flat top. Full Auto.
M16A4 - Flat top. 3 round burst.
There were other changes between the various models but quite minor. I also might have mixed up the 3 rd burst between the A3 and A4 as I misremember if the US military decided it was better to have full auto or not. As for A3/A4 have M4 feedramps - that is incorrect. Only M4's have M4 feedramps (in military rifles) and I believe the M4 is only at the A2 for improvements.
No difference between A3 and A4 in civilian terms. A flattop is a flattop.
From what I've noticed, Rock River Arms calls their flattop CARA4, Colt calls them AR15A3, Armalite calls them M15A4. I think it's a copyright/trademark issue with civilian ARs.
I could be wrong on this one though.
From what I've noticed, Rock River Arms calls their flattop CARA4, Colt calls them AR15A3, Armalite calls them M15A4. I think it's a copyright/trademark issue with civilian ARs.
I could be wrong on this one though.
dangertree
Business Rep
- Location
- NL/ON/FL/PL
"No difference between A3 and A4 in civilian terms. A flattop is a flattop."
That's what I thought too.
That's what I thought too.
So far we have a bunch of varying opinions, so who is correct? I don't know but I'll give you my version;
Either can have M4 feedramps, normally an A3 is a plain jane flattop. When most people refer to A4's in regards to AR15's, I believe that they are referring to those that come with the T numbers in the slots.
That's my 2 cents worth, am I right or is one of the other posts above? In the world of the internet you'll probably never get a concrete answer.
Either can have M4 feedramps, normally an A3 is a plain jane flattop. When most people refer to A4's in regards to AR15's, I believe that they are referring to those that come with the T numbers in the slots.
That's my 2 cents worth, am I right or is one of the other posts above? In the world of the internet you'll probably never get a concrete answer.
dangertree
Business Rep
- Location
- NL/ON/FL/PL
I know with Stag Arms they don't use A3 or A4 etc. We order the "Flattop Upper Receiver" with or without T-Marks, and with or without M4 ramps.
The lazer etched T-marks cost more, the M4 ramps don't.
The lazer etched T-marks cost more, the M4 ramps don't.
Agreed. That's why I like to go with the description rather than A3 A4 etc.
Glock4ever
CGN Ultra frequent flyer
- Location
- Edmonton, AB
I could only find this post but I wish I could find the actual source of info for this one. Oh yeah, when talking about A3/A4, I am operating under the assumption that we are talking US military nomenclature not just whatever some non-milspec company is throwing out there in which case I agree with the above posts that there is no rhyme or reason.
Colt AR-15
The civilian version of the M-16, called the AR-15, is a single-shot weapon manufactured by Colt. The Colt AR-15 is used by private citizens for everything from deer hunting to plinking at cans.
Any weapon which shoots automatically, more than one shot, without manual reloading, by a single function of the trigger, is a machinegun as defined in 26 U.S.C. 5845(b), the National Firearms Act (NFA). In addition, the definition of a machinegun also includes any combination of parts from which a machinegun may be assembled, if such parts are in possession or under the control of a person. An AR-15 type assault rifle which fires more than one shot by a single function of the trigger is a machinegun under the NFA. Any machinegun is subject to the NFA and the possession of an unregistered machinegun could subject the possessor to criminal prosecution. ATF has encountered various AR-15 type assault rifles such as those manufactured by Colt, E.A. Company, SGW, Sendra and others, which have been assembled with fire control components designed for use in M16 machineguns. The vast majority of these rifles which have been assembled with an M16 bolt carrier, hammer, trigger, disconnector and selector will fire automatically merely by manipulation of the selector or removal of the disconnector. Many of these rifles using less than these five M16 parts also will shoot automatically by manipulation of the selector or removal of the disconnector.
The Colt AR-15 is a semiautomatic assault weapon as defined in the Gun Control Act of 1968. 18 U.S.C. 921(a)(30). It is generally unlawful to possess or transfer these firearms. 18 U.S.C. 922(v)(1). This prohibition, however, does not apply to any AR-15 that was lawfully possessed on or before Sept. 13, 1994. 18 U.S.C. 921(v)(2).
M16A1 Semiautomatic Rifle
In 1967 the M16A1 was adopted by the US Army. It featured a positive forward assist to help close the bolt when dirty, chromium plated chamber and bore to resist corrosion and an improved gas system with a new bolt buffer designed to reduce the rate of fire on full auto. These improvements, together with a new field cleaning kit and better maintenance instruction, helped to get rid of the reliability problems.
Despite the problems encountered during initial fielding, better training, preventive maintenance, and several design changes, resulted in the weapon that has become the standard issue rifle of the US Army, with some 3,690,000 having been manufactured. The weapon, chambered for 5.56x45mm NATO caliber, has been a mainstay of the U.S. military ever since, and gradually replaced the M14 in U.S. service through the 1960’s.
M16A2 Semiautomatic Rifle
The M16A2 semiautomatic rifle is the standard by which all military rifles of the future will be judged. This variant of the M16 fires a three-round burst in semiautomatic operation. The system incorporates an adjustable rear sight which corrects for both wind and elevation, a heavier barrel with 1-in-7 rifling, and a muzzle compensator to prevent muzzle climb during semiautomatic operation. The M16A2 is capable of firing all NATO standard 5.56mm ammunition and can fire 40mm grenades when equipped with the M203 Grenade Launcher.
The M16A2 replaced the M16A1 in U.S. Army service in 1983. It is essentially an improved M16A1. Major changes include: a switch from full automatic to 3-round burst capability; a heavier barrel; improved sights; new, stronger plastic buttstock, handguard, and pistol grip.The M16A2 has some practical features missing from the M16A1, found on the M4A1 -- the prime examples being the ability to rapidly breakdown the gun and fieldstrip, as well as the high metal parts content.
The M16A2 5.56mm rifle is a lightweight, air-cooled, gas-operated, magazine-fed, shoulder- or hip-fired weapon designed for either automatic fire (3-round bursts) or semiautomatic fire (single shot) through the use of a selector lever. The weapon has a fully adjustable rear sight. The bottom of the trigger guard opens to provide access to the trigger while wearing winter mittens. The upper receiver/barrel assembly has a fully adjustable rear sight and a compensator which helps keep the muzzle down during firing. The steel bolt group and barrel extension are designed with locking lugs which lock the bolt group to the barrel extension allowing the rifle to have a lightweight aluminum receiver.
The M16A2 rifle is a product improvement of the M16A1 rifle. The improvements are:
* a heavier, stiffer barrel than the barrel of the M16A1;
* a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle;
* a new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage;
* an improved rear sight which can be easily adjusted for windage and range;
* a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer;
* a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure;
* a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire;
* a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.
Primary function: Infantry weapon
Manufacturer: Colt Manufacturing and Fabrique Nationale Manufacturing Inc.
Length: 39.63 inches (100.66 centimeters)
Weight, with 30 round magazine: 8.79 pounds (3.99 kilograms)
Bore diameter: 5.56mm (.233 inches)
Maximum range :3,600 meters Maximum effective range:
Area target: 2,624.8 feet (800 meters)
Point target: 1,804.5 feet (550 meters)
Muzzle velocity: 2,800 feet (853 meters) per second
Rate of fire:
Cyclic: 800 rounds per minute
Sustained: 12-15 rounds per minute
Semiautomatic: 45 rounds per minute
Burst: 90 rounds per minute
Magazine capacity: 30 rounds
Unit Replacement Cost: $586
M16A2 Squad Advanced Marksman Rifle [SAMR]
The Squad Advanced Marksman Rifle [SAMR] consists of the Trijicon Advanced Combat Optical Gunsight mounted on top of a M-16A2 with a match-grade heavy barrel and Harris bipod. It is an interim solution. Currently, Marine rifle squads have two sets of distinct weapons: three grenade launchers and three squad automatic weapons. If the experiment proves successful, they could get three SAMs as well. Some squads used SAMs for effective long-range shots against single targets. Others put SAMs in over-watch positions to cover a squad’s movement to an objective, while some used them to scour avenues of approach, gathering on-scene intelligence. The scope, which has a unique reticle pattern with a red chevron for a 300-meter aiming point, also improved the ability to range targets at unknown distances. The chevron’s upside-down V fits squarely over the shoulders of a man-sized target at 300 meters. The 400-, 500- and 600-meter bars just below the chevron also fits within the outer limits of a man’s shoulders at that distance. Marines, shooting the M-16A2 with iron sights, had a first-shot hit rate of 45 percent on targets between 137 and 432 meters. With the SAMR, those rates were 88 percent.
M16A2E4 Semiautomatic Rifle
The M16A2E4 rifle is a standard M16A2 Rifle modified by changing the current upper receiver to a flat-top upper receiver with a detachable carrying handle. The flat-top upper receiver has an integral rail which is utilized (when the carrying handle is removed) to mount optical devices to the weapon. This integral rail has been designed to conform to MIL-STD 1913 and allows common mounting of many different items.
M16A3 Semiautomatic Rifle
The M16A3, which replace the M16A2 in 1994, is basically an M16A2 with full-automatic capability and optional M4A1-style Rail Interface System (RIS). The M16A3 and the M16A4 are identical to the M16A2, but both have the modular upper receiver. The M16A3 is capable of fully automatic fire, like the M16A1, while the M16A4 uses the M16A2's three-round burst mechanism. Additionally, several types of optical sights have been developed for the modular upper.
M16A4 Semiautomatic Rifle
The M16A4 is identical to the M16A3, but can fire single shots or 3-round bursts (no full auto). The M16A4 Rifle is a standard M16A2 Rifle with a flat top upper receiver and detachable carrying handle. The flat top upper receiver has an integral rail that will be utilized (when the carrying handle is removed) to mount optical devices to the weapon. The M16A4 Rifle in combination with the M5 Rail Adapter forms the Modular Weapon System (rifle version) which provide soldiers the flexibility to configure their weapons with those accessories required to fulfill an assigned mission. There are no differences between the internal dimensions of the M16A2 Rifle and the M16A4 Rifle.
M4/M4A1 Carbine
The M4/M4A1 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. A shortened variant of the M16A2 rifle, the M4 provides the individual soldier operating in close quarters the capability to engage targets at extended range with accurate, lethal fire. The M4 Carbine achieves over 80% commonality with the M16A2 Rifle and will replace all M3 .45 caliber submachine guns and selected M9 pistols and M16 rifle series.
After the military conflicts in Panama, the Persian Gulf and Somalia, the need for a shorter version of the M16A2 again appeared. Colt engineers shortened the barrel back to 14.5", contoured the barrel to mount the M203 grenade launcher, and added a collapsible, sliding buttstock. They also created a new upper receiver using a modular sight mounting system for use on a sub-variant. In August 1994, both variations were adopted. The United States Carbine, Caliber 5.56mm NATO, M4 uses the new barrel and collapsible buttstock, but was first issued with the standard M16A2 upper receiver and sights to streamline production, though it now is made with the new modular upper receiver.
The M4 Carbine is similar in design and functioning to the M16 family of rifles, thereby greatly simplifying training, supply, and maintenance. Compared to the M16A2 rifle, the M4 Carbine is 1.3 pounds lighter, 6 5/8 inches shorter with buttstock extended, and almost 10 inches shorter with the buttstock collapsed. The basis of issue plan replaces on a one-for-one basis all caliber .45 submachine guns, selected caliber .45 and 9mm pistols, and selected Ml6A2 rifles. Infantry personnel receiving the M4 include platoon leaders, platoon sergeants, radio-telephone operators, and mortar gunners. The pistols carried by Infantry commanders, executive officers, and operations officers will not be replaced.
M4 SOPMOD Accessory Kit
The Special Operations Peculiar Modification to the M4 Carbine (SOPMOD M4) Accessory Kit Program is sponsored by the United States Special Operations Command and is responsible for procuring and fielding Non-Developmental Item/Commercial Off-the-Shelf (NDI/COTS) components that increase the operational effectiveness of the M4A1 Carbine in both day and night conditions. This allows SOF operators to configure the M4A1 carbine based on mission-specific requirements; kit items increase weapons effectiveness through improved target acquisition and fire control in close-quarters battle and out to ranges of 500 meters, both day and night.
The procurement/fielding of the Accessory Kit (Phase I) is nearly complete, however, the program is looking to continuously improve the existing kit components as well as providing new NDI/COTS technologies to Special Forces. Currently, the Accessory Kit is comprised of the following components: 4X Day Scope, Reflex Sight, Rail Interface System (MIL-STD 1913), Vertical Forward Handgrip, Quick Attach/Detach M203 Grenade Launcher Mount and Sight, Infrared Laser Pointer/Illuminator, Visible Laser, Visible Bright Light, Backup Iron Sight, Combat Sling, Sloping Cheek Weld Stock, Mini Night Sight and 9" M203 Grenade Launcher Barrel.
All kit items currently fielded or in production with the exception of the Mini Night Vision Sight (MNVS). Operational testing completed on MNVS in the third quarter FY 1999, with fielding to follow. Beginning work now on supplemental requirements to SOPMOD Generation II, which begins R&D efforts in FY 2000 and FY 2001. Generation II SOPMOD will concentrate on consolidation of current devices and new capabilities designed to enhance the lethality of the SOF operator.
Colt AR-15
The civilian version of the M-16, called the AR-15, is a single-shot weapon manufactured by Colt. The Colt AR-15 is used by private citizens for everything from deer hunting to plinking at cans.
Any weapon which shoots automatically, more than one shot, without manual reloading, by a single function of the trigger, is a machinegun as defined in 26 U.S.C. 5845(b), the National Firearms Act (NFA). In addition, the definition of a machinegun also includes any combination of parts from which a machinegun may be assembled, if such parts are in possession or under the control of a person. An AR-15 type assault rifle which fires more than one shot by a single function of the trigger is a machinegun under the NFA. Any machinegun is subject to the NFA and the possession of an unregistered machinegun could subject the possessor to criminal prosecution. ATF has encountered various AR-15 type assault rifles such as those manufactured by Colt, E.A. Company, SGW, Sendra and others, which have been assembled with fire control components designed for use in M16 machineguns. The vast majority of these rifles which have been assembled with an M16 bolt carrier, hammer, trigger, disconnector and selector will fire automatically merely by manipulation of the selector or removal of the disconnector. Many of these rifles using less than these five M16 parts also will shoot automatically by manipulation of the selector or removal of the disconnector.
The Colt AR-15 is a semiautomatic assault weapon as defined in the Gun Control Act of 1968. 18 U.S.C. 921(a)(30). It is generally unlawful to possess or transfer these firearms. 18 U.S.C. 922(v)(1). This prohibition, however, does not apply to any AR-15 that was lawfully possessed on or before Sept. 13, 1994. 18 U.S.C. 921(v)(2).
M16A1 Semiautomatic Rifle
In 1967 the M16A1 was adopted by the US Army. It featured a positive forward assist to help close the bolt when dirty, chromium plated chamber and bore to resist corrosion and an improved gas system with a new bolt buffer designed to reduce the rate of fire on full auto. These improvements, together with a new field cleaning kit and better maintenance instruction, helped to get rid of the reliability problems.
Despite the problems encountered during initial fielding, better training, preventive maintenance, and several design changes, resulted in the weapon that has become the standard issue rifle of the US Army, with some 3,690,000 having been manufactured. The weapon, chambered for 5.56x45mm NATO caliber, has been a mainstay of the U.S. military ever since, and gradually replaced the M14 in U.S. service through the 1960’s.
M16A2 Semiautomatic Rifle
The M16A2 semiautomatic rifle is the standard by which all military rifles of the future will be judged. This variant of the M16 fires a three-round burst in semiautomatic operation. The system incorporates an adjustable rear sight which corrects for both wind and elevation, a heavier barrel with 1-in-7 rifling, and a muzzle compensator to prevent muzzle climb during semiautomatic operation. The M16A2 is capable of firing all NATO standard 5.56mm ammunition and can fire 40mm grenades when equipped with the M203 Grenade Launcher.
The M16A2 replaced the M16A1 in U.S. Army service in 1983. It is essentially an improved M16A1. Major changes include: a switch from full automatic to 3-round burst capability; a heavier barrel; improved sights; new, stronger plastic buttstock, handguard, and pistol grip.The M16A2 has some practical features missing from the M16A1, found on the M4A1 -- the prime examples being the ability to rapidly breakdown the gun and fieldstrip, as well as the high metal parts content.
The M16A2 5.56mm rifle is a lightweight, air-cooled, gas-operated, magazine-fed, shoulder- or hip-fired weapon designed for either automatic fire (3-round bursts) or semiautomatic fire (single shot) through the use of a selector lever. The weapon has a fully adjustable rear sight. The bottom of the trigger guard opens to provide access to the trigger while wearing winter mittens. The upper receiver/barrel assembly has a fully adjustable rear sight and a compensator which helps keep the muzzle down during firing. The steel bolt group and barrel extension are designed with locking lugs which lock the bolt group to the barrel extension allowing the rifle to have a lightweight aluminum receiver.
The M16A2 rifle is a product improvement of the M16A1 rifle. The improvements are:
* a heavier, stiffer barrel than the barrel of the M16A1;
* a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle;
* a new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage;
* an improved rear sight which can be easily adjusted for windage and range;
* a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer;
* a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure;
* a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire;
* a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.
Primary function: Infantry weapon
Manufacturer: Colt Manufacturing and Fabrique Nationale Manufacturing Inc.
Length: 39.63 inches (100.66 centimeters)
Weight, with 30 round magazine: 8.79 pounds (3.99 kilograms)
Bore diameter: 5.56mm (.233 inches)
Maximum range :3,600 meters Maximum effective range:
Area target: 2,624.8 feet (800 meters)
Point target: 1,804.5 feet (550 meters)
Muzzle velocity: 2,800 feet (853 meters) per second
Rate of fire:
Cyclic: 800 rounds per minute
Sustained: 12-15 rounds per minute
Semiautomatic: 45 rounds per minute
Burst: 90 rounds per minute
Magazine capacity: 30 rounds
Unit Replacement Cost: $586
M16A2 Squad Advanced Marksman Rifle [SAMR]
The Squad Advanced Marksman Rifle [SAMR] consists of the Trijicon Advanced Combat Optical Gunsight mounted on top of a M-16A2 with a match-grade heavy barrel and Harris bipod. It is an interim solution. Currently, Marine rifle squads have two sets of distinct weapons: three grenade launchers and three squad automatic weapons. If the experiment proves successful, they could get three SAMs as well. Some squads used SAMs for effective long-range shots against single targets. Others put SAMs in over-watch positions to cover a squad’s movement to an objective, while some used them to scour avenues of approach, gathering on-scene intelligence. The scope, which has a unique reticle pattern with a red chevron for a 300-meter aiming point, also improved the ability to range targets at unknown distances. The chevron’s upside-down V fits squarely over the shoulders of a man-sized target at 300 meters. The 400-, 500- and 600-meter bars just below the chevron also fits within the outer limits of a man’s shoulders at that distance. Marines, shooting the M-16A2 with iron sights, had a first-shot hit rate of 45 percent on targets between 137 and 432 meters. With the SAMR, those rates were 88 percent.
M16A2E4 Semiautomatic Rifle
The M16A2E4 rifle is a standard M16A2 Rifle modified by changing the current upper receiver to a flat-top upper receiver with a detachable carrying handle. The flat-top upper receiver has an integral rail which is utilized (when the carrying handle is removed) to mount optical devices to the weapon. This integral rail has been designed to conform to MIL-STD 1913 and allows common mounting of many different items.
M16A3 Semiautomatic Rifle
The M16A3, which replace the M16A2 in 1994, is basically an M16A2 with full-automatic capability and optional M4A1-style Rail Interface System (RIS). The M16A3 and the M16A4 are identical to the M16A2, but both have the modular upper receiver. The M16A3 is capable of fully automatic fire, like the M16A1, while the M16A4 uses the M16A2's three-round burst mechanism. Additionally, several types of optical sights have been developed for the modular upper.
M16A4 Semiautomatic Rifle
The M16A4 is identical to the M16A3, but can fire single shots or 3-round bursts (no full auto). The M16A4 Rifle is a standard M16A2 Rifle with a flat top upper receiver and detachable carrying handle. The flat top upper receiver has an integral rail that will be utilized (when the carrying handle is removed) to mount optical devices to the weapon. The M16A4 Rifle in combination with the M5 Rail Adapter forms the Modular Weapon System (rifle version) which provide soldiers the flexibility to configure their weapons with those accessories required to fulfill an assigned mission. There are no differences between the internal dimensions of the M16A2 Rifle and the M16A4 Rifle.
M4/M4A1 Carbine
The M4/M4A1 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. A shortened variant of the M16A2 rifle, the M4 provides the individual soldier operating in close quarters the capability to engage targets at extended range with accurate, lethal fire. The M4 Carbine achieves over 80% commonality with the M16A2 Rifle and will replace all M3 .45 caliber submachine guns and selected M9 pistols and M16 rifle series.
After the military conflicts in Panama, the Persian Gulf and Somalia, the need for a shorter version of the M16A2 again appeared. Colt engineers shortened the barrel back to 14.5", contoured the barrel to mount the M203 grenade launcher, and added a collapsible, sliding buttstock. They also created a new upper receiver using a modular sight mounting system for use on a sub-variant. In August 1994, both variations were adopted. The United States Carbine, Caliber 5.56mm NATO, M4 uses the new barrel and collapsible buttstock, but was first issued with the standard M16A2 upper receiver and sights to streamline production, though it now is made with the new modular upper receiver.
The M4 Carbine is similar in design and functioning to the M16 family of rifles, thereby greatly simplifying training, supply, and maintenance. Compared to the M16A2 rifle, the M4 Carbine is 1.3 pounds lighter, 6 5/8 inches shorter with buttstock extended, and almost 10 inches shorter with the buttstock collapsed. The basis of issue plan replaces on a one-for-one basis all caliber .45 submachine guns, selected caliber .45 and 9mm pistols, and selected Ml6A2 rifles. Infantry personnel receiving the M4 include platoon leaders, platoon sergeants, radio-telephone operators, and mortar gunners. The pistols carried by Infantry commanders, executive officers, and operations officers will not be replaced.
M4 SOPMOD Accessory Kit
The Special Operations Peculiar Modification to the M4 Carbine (SOPMOD M4) Accessory Kit Program is sponsored by the United States Special Operations Command and is responsible for procuring and fielding Non-Developmental Item/Commercial Off-the-Shelf (NDI/COTS) components that increase the operational effectiveness of the M4A1 Carbine in both day and night conditions. This allows SOF operators to configure the M4A1 carbine based on mission-specific requirements; kit items increase weapons effectiveness through improved target acquisition and fire control in close-quarters battle and out to ranges of 500 meters, both day and night.
The procurement/fielding of the Accessory Kit (Phase I) is nearly complete, however, the program is looking to continuously improve the existing kit components as well as providing new NDI/COTS technologies to Special Forces. Currently, the Accessory Kit is comprised of the following components: 4X Day Scope, Reflex Sight, Rail Interface System (MIL-STD 1913), Vertical Forward Handgrip, Quick Attach/Detach M203 Grenade Launcher Mount and Sight, Infrared Laser Pointer/Illuminator, Visible Laser, Visible Bright Light, Backup Iron Sight, Combat Sling, Sloping Cheek Weld Stock, Mini Night Sight and 9" M203 Grenade Launcher Barrel.
All kit items currently fielded or in production with the exception of the Mini Night Vision Sight (MNVS). Operational testing completed on MNVS in the third quarter FY 1999, with fielding to follow. Beginning work now on supplemental requirements to SOPMOD Generation II, which begins R&D efforts in FY 2000 and FY 2001. Generation II SOPMOD will concentrate on consolidation of current devices and new capabilities designed to enhance the lethality of the SOF operator.
I would suggest the Wikipidea page as a very good read...
http://en.wikipedia.org/wiki/M16_rifle
It accurately notes that the original gun was the Armalite AR-15 (developed in the late 1950's) and that Colt later bought the rights to the AR-15 from Armalite. Greentips pet peeve is that the AR-15 is NOT a variant of the M16 as CFC and our firearms legislation likes to contend... in fact the M16 is a variant of the AR-15 (but that's a whole other discussion
).
Colt's first two models produced after the acquisition of the rifle from ArmaLite were the 601 and 602, and these rifles were in many ways clones of the original ArmaLite rifle (in fact, these rifles were often found stamped Colt ArmaLite AR-15, Property of the U.S. Government caliber .223, and no reference to being a M16). The 601 and 602 are easily identified by their "slab-sided" lower receivers without the commonly found "fencing" around the magazine well, and in certain cases their green or brown furniture. The 601 was adopted first of any of the rifles by the USAF, and was quickly supplemented with the XM16 (Colt Model 602) and later the M16 (Colt Model 604) as improvements were made. There was also a limited purchase of 602s, and a number of both of these rifles found their way to a number of Special Operations units then operating in South East Asia, most notably the U.S. Navy SEALs. The only major difference between the 601 and 602 is the switch from the original 1:14-inch rifling twist to the more common 1:12-inch twist. These weapons were equipped with a triangular "Dove Tail" charging handle and a "Nipple Less" bolt hold open device. The bolt hold open device had to be engaged with a bare thumb or a thumb nail because of the lack of a nipple.
The Wikipdia page link gives an excellent description of the various Military models M16A1, M16A2, M16A3, M16A4 and the M4 Carbines as well as the C7 & C8 International Variants.
Here (on the same page link I noted above) is the clearest discussion that I've ever seen on the confusion in the commercial market over some manufacturers using the A3 designation and some using the A4 designation:
Many commercial gun/manufacturer are using whatever "name" designation they like to try to make their firearm sound like it's close to the same as the military weapon but reality is that commercial guns are NOT M16's or M4's. They may look similar and they may be built in similar ways but they are not truly "Mil-Spec" in the real definition of the word (that's a whole other discussion).
That's not to say that some commercial guns aren't used by military units (many of the commercial manufacturers have sold guns to military buyers) but don't confuse that with the US Military Rifle M16A1 or A2 or A3 or A4 or the M4 as currently being purchased by the US government and issued to the troops.
Mark
http://en.wikipedia.org/wiki/M16_rifle
It accurately notes that the original gun was the Armalite AR-15 (developed in the late 1950's) and that Colt later bought the rights to the AR-15 from Armalite. Greentips pet peeve is that the AR-15 is NOT a variant of the M16 as CFC and our firearms legislation likes to contend... in fact the M16 is a variant of the AR-15 (but that's a whole other discussion
).Colt's first two models produced after the acquisition of the rifle from ArmaLite were the 601 and 602, and these rifles were in many ways clones of the original ArmaLite rifle (in fact, these rifles were often found stamped Colt ArmaLite AR-15, Property of the U.S. Government caliber .223, and no reference to being a M16). The 601 and 602 are easily identified by their "slab-sided" lower receivers without the commonly found "fencing" around the magazine well, and in certain cases their green or brown furniture. The 601 was adopted first of any of the rifles by the USAF, and was quickly supplemented with the XM16 (Colt Model 602) and later the M16 (Colt Model 604) as improvements were made. There was also a limited purchase of 602s, and a number of both of these rifles found their way to a number of Special Operations units then operating in South East Asia, most notably the U.S. Navy SEALs. The only major difference between the 601 and 602 is the switch from the original 1:14-inch rifling twist to the more common 1:12-inch twist. These weapons were equipped with a triangular "Dove Tail" charging handle and a "Nipple Less" bolt hold open device. The bolt hold open device had to be engaged with a bare thumb or a thumb nail because of the lack of a nipple.
The Wikipdia page link gives an excellent description of the various Military models M16A1, M16A2, M16A3, M16A4 and the M4 Carbines as well as the C7 & C8 International Variants.
Here (on the same page link I noted above) is the clearest discussion that I've ever seen on the confusion in the commercial market over some manufacturers using the A3 designation and some using the A4 designation:
Some confusion continues to exist regarding the M16A3. It is often described as the fully-automatic version of the M16A4. Descriptions of the M16A3 that claim that it shares the M16A4's Picatinny rail are incorrect. This misunderstanding most likely stems from the usage of the A2 and A3 designations by Colt and other manufacturers of weapons before the official adoption of the M16A4. Many manufacturers of civilian AR15 rifles designate variants with flat top configurations as "A3" rather than "A4." Colt used the "A3" designation in the hopes of winning military contracts as they also did with the terms, "M4" and "M5."
M16A4
The M16A4, now standard issue for front-line U.S. Marine Corps and some U.S. Army units, replaces the combination fixed carry handle/rear iron sight with a MIL-STD-1913 Picatinny rail, allowing for the rifle to be equipped with a carry handle and/or most military and consumer scopes or sighting systems. Most of the U.S. Marine Corps' M16A4s are equipped with a Knight's Armament Company M5 RAS handguard, allowing vertical grips, lasers, tactical lights, and other accessories to be attached. In U.S. Army Field Manuals, M16A4s fitted with the RAS are sometimes referred to as M16A4 MWS or Modular Weapon System. This model retains the 3-round burst mode of the M16A2.
M16A4
The M16A4, now standard issue for front-line U.S. Marine Corps and some U.S. Army units, replaces the combination fixed carry handle/rear iron sight with a MIL-STD-1913 Picatinny rail, allowing for the rifle to be equipped with a carry handle and/or most military and consumer scopes or sighting systems. Most of the U.S. Marine Corps' M16A4s are equipped with a Knight's Armament Company M5 RAS handguard, allowing vertical grips, lasers, tactical lights, and other accessories to be attached. In U.S. Army Field Manuals, M16A4s fitted with the RAS are sometimes referred to as M16A4 MWS or Modular Weapon System. This model retains the 3-round burst mode of the M16A2.
Many commercial gun/manufacturer are using whatever "name" designation they like to try to make their firearm sound like it's close to the same as the military weapon but reality is that commercial guns are NOT M16's or M4's. They may look similar and they may be built in similar ways but they are not truly "Mil-Spec" in the real definition of the word (that's a whole other discussion).
That's not to say that some commercial guns aren't used by military units (many of the commercial manufacturers have sold guns to military buyers) but don't confuse that with the US Military Rifle M16A1 or A2 or A3 or A4 or the M4 as currently being purchased by the US government and issued to the troops.
Mark
Any upper can have M4 feed ramps. It has nothing to do with the A2, or A3 or A4 designation. I've seen M4 feed ramps on 10.5" A2 uppers. It's all a matter of what the manufacturer wants to do.
For a while there a year ago everyone was asking for M4 feed ramps... because the Military guns had them all of a sudden civilians wanted to have it too. That demand got commercial manufacturers to start putting them onto many of their civilian models... regardless of any actual need for them.
Mark
dangertree
Business Rep
- Location
- NL/ON/FL/PL
T-Marks = the white reference numbers on top of the receiver. T = Top
On a quadrail you'll also see R on the right rail, L on the Left and B on the Bottom.
On a quadrail you'll also see R on the right rail, L on the Left and B on the Bottom.
I love threads like this, I always end up learning something, but since I am a total newb to AR's and in the midst of starting a build with a Armalite lower, I felt the need to barge in and ask wtf are T-Marks
Numbers screened onto the top of the upper receiver (flat tops) designating each notch so that you can easily find that notch the next time you want to mount your optics. T market #8 may be where you put your EOTech so next time you take it off then put it back you know instantly where to put it.
As far a civy AR goes your options are:
Typical Upper receiver configurations nomenclature in a nutshell:
A1 - Carry handle with sight (no elevation)
A2 - Carry handle with sight, elevation adjustable
Flattop
Options are basically an endless list, here is a sample:
M4 ramps
T-marks
twist rates (1/7, 1/9, ~1/8, 1/12)
barrel length (<10, 10.25, 10.5, 11.5, 14.5, 16, 18.x, 20, >20)
barrel profil (HBAR, Bull, Government, lightweight, M4, mid-weight)
Gas system length (Rifle, Mid-length, Carbine, pistol)
Chromed barrel
Chromed extension
.223 SAMMI chamber vs 5.56 chamber
MRP (Monolithic rail platform) from LMT
etc.....
Typical Upper receiver configurations nomenclature in a nutshell:
A1 - Carry handle with sight (no elevation)
A2 - Carry handle with sight, elevation adjustable
Flattop
Options are basically an endless list, here is a sample:
M4 ramps
T-marks
twist rates (1/7, 1/9, ~1/8, 1/12)
barrel length (<10, 10.25, 10.5, 11.5, 14.5, 16, 18.x, 20, >20)
barrel profil (HBAR, Bull, Government, lightweight, M4, mid-weight)
Gas system length (Rifle, Mid-length, Carbine, pistol)
Chromed barrel
Chromed extension
.223 SAMMI chamber vs 5.56 chamber
MRP (Monolithic rail platform) from LMT
etc.....
Wow, I am almost sorry that I asked...ust kidding though, the site is a great resource.
To clarify, and the reason for my question is that I see a 7.5" AR listed on EE that is specified as a RRA LAR-15 lower with an A3 upper and was just wondering if the is a major difference between this being offered and the RRA Lar15 A4 pistol (Questar)...
To clarify, and the reason for my question is that I see a 7.5" AR listed on EE that is specified as a RRA LAR-15 lower with an A3 upper and was just wondering if the is a major difference between this being offered and the RRA Lar15 A4 pistol (Questar)...
Glock4ever
CGN Ultra frequent flyer
- Location
- Edmonton, AB
Mark, if we are talking military nomenclature the M16 series don't have M4 feedramps - it was a design "change" to allow Colt to be able to trademark the "M4" name. Remember that whole goofy lawsuit with Bushmaster, hence why there is M4-like or M4gery. I am not saying you can't have a civilian AR15 with M4 feedramps but you won't find M4 feedramps in the US or CAD military on the M16, C7 or C8 series rifles; only on the M4 series. That is reason why I said if we are going by Military nomenclature; otherwise all bets are off.
The gun that guy is advertising is a non-commercial "Build". It's not an RRA, just the lower is RRA according to the seller so it's not a factory gun. Who knows what upper it is or who built it... he doesn't really state that info.
You'd have to ask him why he calls it an A3 upper. As you pointed out, the RRA pistol is advertised as an A4 upper. All RRA flat-tops are referred to as A4's.
Mark
