SAR-80 Kit Build – Barrel

The SAR-80 kits are at their new homes (except for Chuck’s, I am holding it hostage so he will have to come visit Tucson) and I can’t believe how similar they are to AR-180’s.

Most of the discussion about the builds is happening over at the new builders forum, Armorer’s Alliance. There are two threads going right now here and here.

Mine will be documented here as well.

First we start with the barrel. Since barrels can no longer be imported these barrels were cut into pieces with a chop saw. Did I mention that these were brand new guns before they were demilled for importation. What a shame. The old barrel pieces need to be removed so that new barrel dimensions can be put together and a new barrel made. The barrel stub can be removed in a number of ways and since I have the tooling I chose to hold the stub in vice blocks and use a reaction wrench to separate the trunion from the barrel.

Once I got the trunion off I discovered that it is different from the 180.

Next to get an idea of the dimensions of the original barrel I set it up next to an original 180 barrel. The similarities were striking. I guess I should not have been surprised since this gun was originally designed by Sterling and was known as the Sterling Automatic Rifle. The chamber end matches exactly and the dimension to the front sight base boss looks very close as well.

Lets see if the 180 barrel fits in the trunion. Yep it sure does.

Lets see if the length to the front sight base looks close. Yep that works too. If fact everything lines up with this original 180 barrel. Know we can put together a set of prints using some of the measurements from the 180 barrel and the remaining SAR-80 barrel pieces.


I have ordered a barrel from numrich for the 180B and plan to modify that to fit this gun rather than use this original 180 barrel.

Next up, what the heck are we going to do with the upper? Weld? New from scratch? Join the discussion at the Armorer’s Alliance and lets work it out together.