AR180B Gunsmithing; A Cautionary Tale

Good friend of the site Oscar sent me an upper that another gunsmith attempted to remove the barrel on. He got it back from said gunsmith with the message that he was unable to remove the barrel and afterwords he was unable to tighten the barrel back up.

What many do not know is that the AR180B has a unique method of barrel retention and it is not at all obvious.

If we look at a bare trunion you will note that it has a large hole through the middle with a small step.

The barrel for this gun uses an AR15 barrel extension that is turned down and press fit into this trunion. That’s it! Nothing else. Just a press fit.

What happens then when the unsuspecting gun plumber puts a barrel wrench on the barrel and clamps that flat sided receiver in his vise? It makes funny noises and turns the extension in the trunion. Not good. Oscar mentioned that it shot terrible after he got it back and I suggested he send it to me for inspection. It didn’t take long to figure out my initial thoughts were correct.

Now how do I fix it so it is safe to shoot? I want to thank Oscar for being patient with me as I have had his upper for quite some time while I try to figure out what to do.

I settled on a shallow pin. I wanted it to not show unless you were looking for it and still be able to hold everything secure.

Sneaking the Tig torch in between the bosses was challenging but ended up with good penetration after I got the amperage dialed in.

So what is the right way to remove a barrel for the 180 Bravo? Use a modified reaction wrench. Do not put any twisting force on the receiver itself.

New AR-180S Shorty Parts Have Arrived

I now have everything needed to offer shorty conversions or to sell the parts outright if you want to roll your own. CNC machined from billet steel these new hand guard caps will retain the cut down hand guards on an AR180 or 180B. Shoot me a message through the contact form if you need more details.

AR180S Pistol Grips Ready To Ship

Well I have 3 ready to ship.

I have reworked the model and done modifications to my printer and I am happy with how they are printing now.

I have also decided to put them up for sale and will print and fill orders as they come in. That might take awhile to fill as they take quite some time to print. 18+ hours to be exact.

These can certainly be used as is but really need to be sanded, polished, possibly even painted.

Here is an early prototype that I sanded and rounded the edges then polished.

First 3 will ship right away, first come, first served. Just click on the link at the top of the page to take you to the Shopping Cart.

I am really looking forward to getting some pictures of how your pistol grips turn out!

As always use the “Contact Me” link to send me an email if you have any questions.

 

 

A Day in the Shop

Spent a full day in the shop just playing with stuff and it was very relaxing.

Started off with a new purchase that arrived while I was out of town.

The KGB Stinger47 pistol strut. It is designed for AK pistols and allows the use of a TailHook pistol brace. For those that haven’t heard the ATF now allows you to add a pistol brace without turning it into an SBR. I kept seeing Josh at Stormwerkz posting pics of his on different guns, including an AR180B. I had to snag one. Click here for info.

I have one of my pistol lowers that has been modified with two holes drilled and tapped so I didn’t need an adapter for mine.

 

I then decided to try out the folding mechanism I have. I was thinking I would fold it to the left like an original 180 but it blocked the safety so to the right it is.

I could not use the 180B charging handle so I swapped out the bolt carrier for one that I had modified back in the day. Stuck a Sterling charging handle in and Bob’s your uncle.

It then struck me that I have always wanted to add an original 180 ambi safety on a 180B so I fanally said “No more thinking about it, just do it.”

Took a spare safety that I sell as part of the Lower Completion Kit and broke out the tig welder. Stuck a big blob on the end then started turning and milling and filing and cutting a grove for the snap ring.

I then took it back apart and ran it through my table top park tank. The welded on section did not get as dark as I would have liked. Maybe I need to try a different filler metal next time.

 

I’m really happy with how it turned out even though it took me a long time.

A day in the shop is cheaper than therapy.

I also hand fitted and bagged up the last of the Lower Completion kits. If you are thinking about getting one or need the parts for spares just hit up the link at the top of the page. I am off next week and can get them shipped out right away.

If you are on Instagram give me a follow (BigRix)

I often post pics of what I am up to when I don’t have time to do a full blown blog post.

 

What 3D Printer Do I Use?

I’ve had several people email me asking what 3D printer I am using.

The Monoprice Select Plus has served me very well over the last few months. I have done very little to modify it other than to add a different type of spool holder. I am providing an Amazon link below if any one is interested in picking one up themselves.

Monoprice Select Plus

I have the final version of the AR180S pistol grips design ready to go and hope to get a few printed off this weekend. Each one takes about 15 hours to print so it will be awhile before I have them ready to sell. My plan is to get a small batch together then put up a for sale post. I don’t want to take money ahead of time or put together a waiting list. I think this will work out best for all parties involved.

Make sure you are subscribed so you get notified when they go up for sale.