Late Sterling AR180 Headspace Issues

Had reader Scott contact me about his late Sterling AR180 that was sticking cases in the chamber and he determined that it was a headspace issue. He lives a couple hours away so he dropped by to have me set the barrel back. It wasn’t until I got the barrel removed that I found the real problem. It wasn’t a barrel set back issue at all like I originally thought. The problem was that the lugs in the trunion had worn out prematurely.

I suspect the heat treat was done incorrectly on the trunion as this gun showed signs that it had not been shot much or abused.

I know this is a sample size of one but could this explain why there were more Late, blued Sterlings built but the black ones are much more prevalent in the market today? Did many of those late Sterlings fail in a similar fashion? Has anyone seen similar problems in guns you have owned before?

For those that don’t know Sterling production went from serial number S15001-S27363 spanning the years 1979-1985 for a total of 12,362 rifles. I have determined that the switch from Black painted to Blued finish took place around serial S20000. That puts the mix at approximately 5000 black and 7300 blued.

Staying Busy

First I must apologize for not posting more often. Most of my day to day happenings end up on social media. If you are not following me on Instagram then you are missing a lot.

Lets back up a week or two to my T91 Pistol brace project.

It started with inspiration from Red_McCloud on the retro AR forums. He designed and printed a retro pistol brace and I needed something similar for my shorty T91 clone build.

Red_McCloud version top T91 version bottom

Mine makes use of the butt stock parts available from

These two pistol braces are not compatible in case you were wondering. The tube diameter and bottom lug on the T91 stuff is larger in dimensions.

Next I started work on prototyping a straight 180B style charging handle for the BRN-180.

Made a quick one out of aluminum to check dimensions and function. Works fine with one exception. Charging the weapon with a traditional grip when the dust cover is closed causes the dust cover to hit your hand and somewhat inhibits a full stroke. A change in hand position will be required to eliminate this.

Based off some of my 3D printed tools I use in the shop I designed these Field Strip Stands for use with any AR180, AR180B, or AR18. I am going to offer these through soon.

Finally I have been strugling to locate fire control parts for some folks so I decided to try something radical and see if I could adapt a drop-in AR15 trigger into an AR180.

I got it physically located so it hit the firing pin at the right angle and cocks correctly when the bolt carrier cycles. I have no idea if it will actually have enough power to fire a primer. Range testing to follow. Ranges are closed in AZ right now. If it does fire I have to figure out how to get the safety to work.

If this doesn’t pan out I will still be able to use parts of this design to work up a set of anti walk pins for the AR180.

Finally I was able to get to the range last week before they closed to shoot my AR18 for the first time.