Armalite sold the mfg rights of the AR15 to Colt who marketed it to the US Govt, early in this process the AR15 went through a "bad" period, Armalite, in hope of capturing military contracts designed the AR18 to compete w/the AR15, it used the same basic locking system/action as the AR15 but used a piston assembly rather than direct gas impingement as on the AR15, it also utilized stamped steel for the upper/lower receivers rather than the AR15's forged receivers & Armalite believed the rifle would be more reliable, simpler, and less expensive to buy & operate. It was tested by the Army in 64-65, at the time it wasn't near fully developed & was "passed" over, later it was retested, around 1969, & found to be a reliable & accurate weapon but at this point the M16 was already in service in large numbers so it's chance had passed. It was developed into the AR180, a semi-auto variant & built/sold by Armalite in Costa Mesa Ca, later it was license built by Sterling in UK & Howa in Japan. The rifle pictured in the album is an original Costa Mesa (USA mfg) AR180.
Album by willyp. Photos by willyp. 1 - 42 of 42 Total. 16860 Visits.
AR18/180 & AR15/M16 rifles A comparison photo of: Top: Armalite AR180 Mddl: M16A1 Bttm: M16A2 The AR180 was designed to address some of the perceived "problems" of the AR15/M16 early in it's life.
Ar180 w/accessories Right view of the AR180 w/Armalite mount/scope combo, sling, M7 bayonet/scabbard. Many early design features of the AR15 were found in the AR180, sling swivel at base of grip, multi-lug locking bolt, 2 piece "swing open" upper/lower receiver combination, early 3 prong "duckbill" style compensator, mounting for the standard US M7 bayonet.
Ar180 view w/M7 bayonet affixed Some of the changes in the design of the AR180 vs the AR15/M16, the AR180 used a gas piston system rather than direct gas impingement, an attempt to cure the "fouling" problems w/the early M16's (which wasn't really a problem w/the design), this also enabled Armalite to do away w/the rear recvr xtension (or buffer tube) which made it easier to incorporate a folding stock which had been a difficult problem w/the AR15/M16, it also used stamped steel upper/lower receiver halves which were easier & cheaper to mfg.
Ar180 right view The general layout of controls etc & the basic design follow the AR15 pretty well.
Ar180 w/stock folded Here you can see how compact the rifle is with the stock folded, operation of the stock was a simple procedure & the stock simply folded to the left & locked on a pin in the left receiver wall, fire control was operable from both sides so folding the stock did not interfere w/operation.
Buttstock Right view, simple plastic buttstock w/rubber buttplate, stock was thin & folded easily.
Action right w/stck folded You can see the selector lever here on the right side, the mag release & charging handle.
Ar180 R action
Top rear view of receiver Here you can see the rear sight (compare w/pics of the AR15/M16), stock fold mechanism & the scope base which is an integral part of the upper receiver.
Action w/ejection port door open
Armalite scope assembly The scope is the same as the AR15 3x20 scope but is marked Armalite, the mount is specific to the Ar180 & has a spring loaded "pin" at the rear that fits against the rear sight base, you push back w/the pin against the base until the mount slips over the base rails on the upper receiver then the spring pushes the mount forward to it's lock position, the lever at the bottom front of the mount is then used to lock the mount/scope assembly into position. Note also the seperate charging handle which is not part of the bolt carrier, it fits into a cutout in the carrier & must be removed to get the carrier/bolt group out of the receiver.
Forend right side The AR180 uses an upper/lower component handguard set like the later M16A2 but the AR180 handguards are still 2 different pieces which are not interchangeable (which the M16A2 handguards were) like the earlier M16-M16A1 triangular right/left sets.
Right side muzzle w/M7 bayonet affixed The standard US M7 bayonet for the M16 fits the AR180 rifles. Also note the straight 3 prong "duckbill" compensator, very similiar to the original early AR15 "duckbill" that was replaced early in service by the "improved" 3 prong.
Muzzle close-up A detail view of the right side of the muzzle showing the front sight, sling seivel, forward barrel which was 1/12 twist, same as the m16 of the era & the "duckbill" flash suppressor which appears to be the same as the early AR15/M16 model except the AR180 uses a nut between the suppressor & barrel to lock against, also note the suppressor is fitted w/"rings" which enable use of rifle grenades.
AR180 w/action opened Same concept as the AR15/M16, upper/lower receivers seperate at rear & are hinged at front allowing removal of bolt carrier/bolt group & gas piston system through rear of upper receiver for field maintenance.
Bolt/carrier group. Action open for maintenance, carrier spring guide rods/receiver locking assembly at upper left, removeable charging handle upper right, bolt carrier/bolt group w/springs in center, upper/lower receiver receiver sections hinged up & ejection port door open.
Magazine, 20rd The AR180 used basically the same 20rd magazine design as the M16 w/the difference being the location of the cut for the mag lock button: Left: AR15/M16 mag, no cutout on right side Right: AR180 mag, thin cutout on right side for lock button
Mag, 20rd, left sides Left: AR15/M16 mag note rectangular cutout on left side Right: AR180 mag, smooth on left side. It should be noted that it's fairly easy to modify AR15 mags to work in an AR180 & vice/versa, also the currently mfg AR180B by Armalite uses standard AR15/M16 mags in it's design.
Mag followers Left: Early AR15/16 20rd follower, alloy. Right: AR180 mag, this mag has a black plastic follower but as far as I know it should be alloy like the Ar15 mag on right, this follower may have been put in as a replacement/repair.
AR180 vs AR15/M16 floorplates Top: Armalite AR18/AR180 Bttm: Colt AR15/M16, note the .223 marking on the Colt mag, this reportedly was used up to 1969 when it was changed to 5.56 The floorplates, followers, springs etc are actually interchangeable between the mags, the bodies are also identical w/the exception of the cutout for the mag button lock as shown/described previously.
Ar180 scope marking Top view of the Armalite marked scope/mount set.
Ar180 scope mount View from the left front of the mount, the lever at left is the locking lever, the rear of the spring loaded "pin" which butts against the rear sight base is at right.
Ar180 scope rear view Another view of the scope showing the rear lens, focus ring & "pin".
Ar180 muzzle left side Early "duckbill" style AR15/M16 type suppressor from right & different AR180 (vs AR15/M16) front sight.
Muzzle w/bayonet affixed left view The rifle was designed to utilize all the standard US military accessories of the AR15/M16, bayonet, sling (in this case the M1 type web sling), & cleaning gear.
Front sight & handguard detail View of the front sight base & post (standard AR15/m16 early round post), also note the cooling vent on top of the handguard.
Top view of forend Multiple cooling vents, flat top w/serrations adding strength, the AR180 guards were 2 piece, a top & bottom compared to the AR15/M16 (early triangle guard models which were a right & left side), neither the AR15/M16 or the AR180 were interchangeable although the later M16A2 variant w/round handguards had a top & bottom the A2 guards could be used top or bottom.
Left forend view
Lower view of AR180 forend Note the bottom cooling vents & their locations compared to the upper handguard layout.
Left action view A detail pic of the forward left side action area showing the stamped/spot welded mfg method, Armalite logo, front hinge pin & the pin that fits into a spring lock on the buttstock holding it in place when the stock is folded.
Left action view w/scope mounted
Left side action Receiver markings, selector switch, stock lock pin & mount locking system can all be seen fairly well.
AR180 grip Different style of grip used on the AR180 vs the AR15/M16, note the sling swivel mounted on the grip base which was also part of the early AR15/M16 design.
Let upper rear receiver section Here you can see the rear sight, directly behind it the lever that locks/unlocks the upper/lower receiver halves (compared to the takedown pin in the AR15/M16) & the buttstock hinge, at the top of the hinge is the button which releases/locks the stock.
Stock hinge A detail view of the stovk hinge & latch w/the stock folded. On the right is the latch mechanism w/a small "buttons" at the top & bottom which are spring loaded, the "arms" on the hinge at left simply swing over the buttons which then lock into holes in the arms, to open just push on the buttons.
Action view w/stock folded When folded the stock held firmly by a pin which locks into a spring latch on the left side of the buttstock, with the stock folded the selector lever is covered on the left side but the lever is ambidextrous & can be worked from the right side also.
Buttstock Top view of the buttstock & hinge showing how narrow the stock is, in spite of this it's very comfortable, much more than an AR15 collapsible stock (the early versions anyway) & the one on this rifle locks up solidly.
Buttstock left side Here you can see the slot for the lock pin, the slot in the square plate on the stock contains an "H" shape spring, when the stock is folded this slot fits over the pin in the left side of the receiver, the pin then locks on the H spring holding the stock in the folded position.
Ar180 buttplate Simple rubberized buttplate.
AR180 left w/stock folded The rifle is very accurate, comfortable & solid, I'm very impressed w/it & is a great addition to an AR15/M16 collection.