Full Auto AR-180 Conversion on Gunbroker

I was alerted to this interesting full auto AR-180 conversion by a reader and I contacted the seller to get more information. I had assumed that all conversions used the same system as the AR-18 but my research shows that there are many different ways to get the job done.


This particular gun also brings to light the crazy gun laws that we have to deal with and in particular those surrounding full auto guns in Connecticut.

First lets see how an AR-18 worked.


You can see in this picture that the upper receiver has two tabs that retain the auto sear. A link is attached to the sear that rides along the bottom of the upper and is tripped by the bolt carrier. The sear acts upon the rear of the hammer. The hammer is different than the one used on an AR-180 as is the disconnector, bolt carrier, and firing pin.

This conversion goes about it in a completely different way.








This conversion is on a Howa AR-180 and it has a sear that acts on the front of the hammer. It appears to have a pivot added to the front of the fire control box and you can just make out the pin location in the picture above. The sear has a tail that is tripped by a piece that was welded on to the bolt carrier. It uses all the original 180 fire control parts with the exception of the disconnector and the safety. The 180 firing pin is also retained.

I wonder if this is how the Widowmaker conversions were done?

Now for the Connecticut twist on this story. It appears that those who drafted their assault weapons ban tried to get machine guns classified as assault weapons and in doing so, left the door open for guns that are full auto only. You can’t own a registered select fire weapon (one that fires Safe/Semi/Full) but you can have a papaered Full auto machine gun (Safe/Full). This gun is one such animal. For those that live in other states, it can be converted back to a select fire configuration.

Please feel free to comment about any conversions you have come across. I think this is a very cool part of the history of the AR-180.

Latest Happenings at AR180S.com

I just wanted to touch base with y’all to let you know what has been happening. My new job has kicked into high gear and it has me out of town most weeks and that has the unfortunate side effect of keeping me away from the blog. I am home this week and hope to have an article of substance before I head back out on the road.

A couple weekends ago I found a reasonably priced Mill/Drill on craigslist. Unfortunately it was a 4 hour drive away. I rented a trailer and my wife and I went on an adventure to go pick it up. It had lead a relatively hard life as a drill for an off-road fabrication company and would need a little TLC. What can I say, I am a sucker for a project.

It is a Jet JMD-18 and it is the perfect size for my home shop. Being a round column it will require special consideration to order of operations to reduce the need for raising the head.IMG_0359 IMG_0360

Got it home and it took some doing to get it off the trailer without a cherry picker but we got ‘er done.

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I had originally intended to modify my drill press and use it for small milling jobs so I had purchased a cross slide vise from Harbor Freight but it just didn’t work out. I returned it and picked up a chain fall that allowed me to put this mill on the table.

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I pulled the spindle apart to get the number off the bearings and put in an order with McMaster Carr. That finished off my weekend as I had to pack and leave town the next morning.


Last weekend the bearings were installed and a run in procedure was initiated.

The head is back together and it runs much quieter.

Cleaning now starts on the table. It stayed locked in one place for years it would seem, so the ways are a little cruddy. A little bit of rust needs to be cleaned off the surface.

Chuck over at the GunLab  keeps cranking out the AR-180B parts and I am hopeful that I will have some kits in my hands soon. Several have emailed me stating their interest and I will be starting up a waiting list. Email me through the contact form and I will put your name on it.





I am also juggling several gun projects myself. I am now on the fence about the 458 SOCOM AR-180B, it may turn into a mid length gas carbine in 5.56. I already have the barrel so it will be cheap but not nearly as cool. I have a Sten MkIII kit that I want to work on after I get the mill up and running. I also want to try my hand an an 80% lower. Not sure which way to go with a buttstock for the AAA SAP. Folder, original, or mill one out of Delrin?

On top of that I have to prepare for a new Advanced Electrical class I am teaching next week and attend a teaching workshop this week.

Brain Overload.



Mystery Bolt: Reader Needs Your Help

A reader sent me some pictures this weekend and we were unable to identify the maker of this bolt. It has many similar attributes to the AR-180 bolt but the dimensions are not the same.

The overall length is 2.75″ and the “tail” is 1.0″ long.

The bearing surfaces look to be in the same place as on the AR-180 bolt, but the tail is too long.

AR180 bolt

AR180 bolt 2


A 5.56 cartridge fits perfectly.

AR180 556 crop


Please comment with your thoughts on this and lets see if we can’t help him figure out what this bolt fits.

Remaining AR180B Bolt Carrier Groups : Sale

Just a few AR180B Bolt Carrier Groups left and these show a little wear.





Sale Price just for my readers, $175 shipped and insured in the CONUS, AK and HI slightly higher.

These show just a little wear and are really quite close to new.

Hit me up through the contact form and we can arrange payment.

Please be aware that I work out of town during the week and the only day I can ship stuff out is on Saturday’s.

New AR-180B Parts are Coming

Big shout out to Chuck over at GunLab.net who has started work on AR-180B parts. First up is the safety and he has worked out an awesome two piece design.

First some pics from Solidworks.

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Here is a video of the safety lever being made.

And a couple pics of the actual part.


Yep, there will be a few available.


The plan is to offer a set of parts that will supplement your AR-15 lower parts kit and allow you to fully populate a Nodak NDS-18S. Previously the only way to do that was to buy a complete AR-180B Rifle and strip out the lower parts. This will allow you to buy a lower, AR-15 lower parts kit, and this lower kit and get a working lower for your AR-180B, AR-180, or Vulcan V18 upper.