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.

 

 

Reader Pics: New Sharpshooter Kit

Got an email the other day and I knew y’all would be interested in it.

A brand new Sharpshooter kit.

 

This one is packaged as coming from Timberline Hawk and differs in construction from my example. The hand guard cover is improved by the addition of Velcro to allow it to be removed easily. The butt stock cover is the real pain in the ass to install. If I made a new version of this I would certainly use Velcro for that as well.

Just for fun I am including a pic from the movie Daylight’s End showing a Sharpshooter in use.

 

Modern AR-180?

I as well as many others have pondered what the AR-180 would have become if it had the same development as the AR-15.

I think I may have found the answer.

The Remington/Bushmaster ACR Advanced Combat Rifle

Designed by MagPul and named the Masada the rights were sold to, and the civilian version is made by Bushmaster.

I snapped a few pics before I left town but it has many features that are directly decedent from the 180.

Look familiar?

More pics to come and I hope to get them both to the range to compare them side by side.