AR-180S Project

The AR-180S project is full steam ahead!

Some time back I purchased a Costa Mesa upper that was still in the white. It was a left over after the plant closed and had never been built. It has some cosmetic issues and I think this is why.



The seller was nice enough to let me borrow an original AR-18S barrel and hand guard retainer. Our agreement specified I could not give out any dimensions. I was more than happy to comply.



He also gave me an incomplete stamping that I worked over to match the original part.

The stamping was torn and on closer inspection I discovered that it was too thick and this explains why it tore when run through the stamping die.

I  had an old C MP C barrel that had been converted for use in a 180 and the rifling near the muzzle was in bad shape. Cut that sucker down I say.



Like all of my previous shorties the hand guard cap was the most troublesome. I worked on it today and closed up the gaps and welded them. Then started shaping and trimming and grinding.


I next started drilling the holes.


Then the most interesting part, forming the locating ring.



Test fitting.


Stamp should be back in the next four weeks I hope and I really want it up and running in time for the SAR West show.

So far I have not cannibalized any guns to make this. That may not last. At the very least I will need to borrow some parts from another gun.

Still to be done.

Drill and pin the front sight base.

Cut the bayonet lug off the front sight base.

Drill gas port.

Find the proper retaining clip for the rear sight assy.

Make an op rod.

Test fire on my 180B SBR lower or Costa Mesa lower if the stamp is back.

Grin from ear to ear.


AR-180 & AR-180B Parts For Sale

Lets call this the “Help Rick Fund His AR-180S Project”

Time to cut loose with some hard to find parts and get my third shorty project kicked into high gear!


Email me for prices at

Trades welcome.

I will leave these up here for a couple weeks and anything left over goes to gunbroker.

First up are new old stock AR-180B bolt carrier assemblies. Brand new, virgin.



Next up are a very limited quantity of our AR-180B lower completion kits that include Original Hammer & Trigger pins.


Early AR-180B knurled charging handles.


Now some vintage parts

Available separately, AR-180 trigger assy, hammer, safety, safety detent, grip screw, and mag catch.


AR-180 Pistol Grips


AR-180 Butt Stock