Identifying Costa Mesa 30 Round Magazines

In the early days of production and sales in Costa Mesa, Armalite offered their own 30 round steel magazines.

These are often misidentified or overlooked because they have no markings at all.

You will notice that the bases plate shown in the picture below have no markings and feature a hole on one end. These are the ones you are looking for. (The top magazine has the incorrect base plate)

Costa Mesa 30 Round Base Plate

Unlike the Sterling magazines, these have no hole on the side of the magazine.

Right side.

Costa Mesa 30 Round Right

Left side.

Costa Mesa 30 Round Left

They also feature a unique spot weld design that I have seen on no other magazines. Three equally spaced spot welds are more prominent than the rest.

Costa Mesa 30 Round Spot Welds

You will also not that these magazines are designed with a full curve and not the partial curve of the Sterling or M16 magazines.

Costa Mesa 30 Round

Good luck with your hunt for these highly desirable magazines.

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Armalite AR-180 Accessories: Sterling Magazines

As you would expect with any gun that is produced, Armalite tried to provide accessories for you to purchase with your new AR-180.

Taken from this pdf available at Small Arms of the World we see many accessories that were available to outfit your new rifle.

Sterling AR-180 Accessories

The subject of this article are the steel Sterling Magazines.

Sterling Mags 4

These rifles shipped with two 5 round or 20 round aluminum alloy magazines and one of the first things many owners did was buy more. These particular steel magazines had an excellent reputation for reliability and durability. Something many aftermarket magazines did not. I’ve had confirmation from several sources that these were the magazines of choice for those lucky enough to own select fire AR-18’s. The original alloy magazines had a reputation for feed lip problems during sustained full auto. They were also advertised to fit the AR-15 as well and if you own both guns, it made sense to buy these magazines.

Here are some examples I own.

Sterling Mags 1

Sterling Mags 2

Sterling Mags 3

They can be identified by several features, the most notable of which is the base plate. Unlike the original Costa Mesa 30 round steel magazine, the base plates are marked as shown. They also feature a single hole, near the top, on each side.

You will also note that the 20 round magazine is unique in that it curved as well. All original alloy magazines are of the straight design.

Now is my time to speculate a little about the 20 round Sterling magazine.

They are very hard to find and I believe that is because many did not buy them. Put yourself in the mindset of a new AR-180 owner. Your rifle came with two 20 round magazines. If you wanted to buy more, would you order more 20 rounders? I wouldn’t, and I think this is why so few are found today.

This example is the only one I have seen in person and you can see from the picture that the condition is not pristine. It actually looked much worse than this when I got it. Covered in rust. I rubbed it down with some gun oil and steel wool and I was able to knock most of the rust off. I don’t know if I will try to get it any cleaner at this point.

Please comment and let me know if you have any more information about these magazines.


Armalite AR-180 Accessories: Sharp Shooter Kit

The Sharp Shooter Kit is an incredibly hard to find accessory that was available for the Sterling AR-180.

I believe these may be the only pictures of said kit on the internet.

Not much is known of these and I am still searching for more information as we speak.

I first heard about the Sharp Shooter Kit in a few forum threads but didn’t even know what it consisted of. In fact I received this kit and didn’t know what I had. I assumed it was some aftermarket accessory that the seller threw in with my gun when he shipped it.


It was only after seeing this scan of an old Armalite hand out, that I put it all together.

Sharp Shooter Kit 1

The Armalite Sharp Shooter Kit consists of a neoprene/nylon cover for the hand guard and butt stock. Perhaps you too have had one of these and didn’t know what it was.

Here you can see the overall view, please note that the velcro strips have been added after the fact. I’m not sure I can remove them without damage to the sleeve.

Sharp Shooter Kit 2

The next picture shows the butt stock or “Cheek Pad” as Armalite calls it.

Shapr Shooter Kit 3

The final picture shows the vent holes that are cut in the top of the hand guard sleeve. There is also one hole in the bottom.

Sharp Shooter Kit 4

One of the points made in the hand out is that it “Increases shooter comfort”. Although I have not had this gun to the range yet I can tell without a doubt, that is true. I shouldered this rifle a few times while shooting these pictures and with the cold temps outside, the cheek pad made for a much warmer place to lay my face.

Please let me know if you have one of these kits as I would like to put up more pictures and compare them to mine.

AR-180B Shorty Project Pt. II

Another updated series of pics from John over at Retro Arms Works.






It will be heading back soon and I will start on the hand guards.

Then it’s off to the range to dial in the gas port and play!

AR-18S Inspiration for the AR-180B Shorty Project

For those not familiar, the AR-18S was the sub-machine gun version of the select fire AR-18. This was the inspiration for my shorty project.



These two pictures started it all.

Pete Fleis did a handful of these conversions and there are some factory made guns.

There are even a very few semi auto AR-180S guns floating around.

While mine will be a pistol to start, I fully intend to sbr it and have it turn out a close match for these two guns.

I have subsequently found a few more pictures of the cool little guns but have yet to come across any documentation about production numbers.

AR-18S Sterling

I believe this to be a factory Sterling AR-18S.


I believe this is a factory AR-180S but the jury is still out.

You will note that there are three types of flash hiders used on these guns. Small conical, Large conical, and standard three prong.

I will leave you with this scan from Small Arms Review that shows the very first carbine prototype. I wonder where this one is now.

First AR-18 Carbine