AR-180 part 2

In part 2 of making the AR-180 we will be looking at the upper receiver and the steps necessary to make one. There are a number of rifles that use the same basic design concept. So this build concept would work for any of them.

This is the AR-18/180.

DSCN2975scAnd a close up of the upper receiver.


A number of other weapons have the same basic upper receiver design. This includes the AR-180B


DSC_2737scThe early Bushmaster rifle


DSC_2739scThe Leader rifle


DSC_2741scAnd the Vulcan V15DSC_2743s

DSC_2744csSome of these have strengthening ribs while other do not.



This is what the flat would look like after the initial pressing. The holes would be alignment holes for set up and the groves would be pressed in.


This pressing shows the unnecessary sheet metal cut away and the remainder of the holes in the receiver.





The other side of the same pressing


At this point there were probably 2 or three ops performed between this pressing and the last one.  The hole has been cut into the receiver for the ejection port and for the bolt operating handle. In addition the first and second bend has been completed.


The other side of the same pressing.


You can now see the upper receiver completely bent and welded.




These 4 holes on both sides of the receiver are to tig weld the barrel extension to the upper receiver.

DSC_2538sThe vertical run of holes is to tig weld the “u” channel that the bolt runs along into the receiver.




Close up of the welding performed to close the upper receiver together.

DSC_2545sOur next post on this type of rifles will be the smaller parts and how they were made.

14 comments to AR-180 part 2

  • JNC

    I noticed the flat at the top has the tabs for the AR18 trip included. The rolled version is for the semi AR180.

    The TIG welding bead on the bottom is better than the originals I’ve seen.

  • JNC

    Add the SAR80 to the list of copies of the AR18/180.

    The SAR80 sheet metal lower is even simpler then the Ar180. It uses some standard AR15 trigger parts but has the auto trip in front of the hammer.

    It uses standard AR15 magazines with the catch made like the AR180 catch just on the other side.

    The carriers, unless you use a dial caliper, look identical.

  • Martin

    Thanks for showing the steps for this. How thick of metal are you using? Are you building an entire rifle or just the receiver?

  • Johnny

    The L85 is basically an this modified to bullpup configuration.

  • snmp

    * ST Kinetics SAR80
    * ST Kinetics SR88
    * Sterling SAR-87
    * Royal Ordnance/BAE Systems SA80/L85
    * Howa Type 89
    * HK G36 /SL8 & SL9
    * HK XWM8
    * Leader T2 MK5

  • atfsux

    Where the hell did you come up with original stampings?!?!

  • Did you by chance get dimensions off these? I would love to make a flat sided version of this upper like the Leader or Vulcan. After seeing and handling the parts, does it look much harder to do than an AK receiver? Perhaps it is the trunion set up that is the sticking point. It just seems so simple to my untrained eye but there must be something difficult about it or is it that is only inexpensive to produce when production is scaled up?

  • Rufus Chucklebutty

    The SA80 first prototype was made from a Sterling arms AR18 reworked into a bullpup format, the production rifle was unfortunately an unlicenced copy full of errors, and the manufacturing cost went into orbit trying to get it to work. The UK had to spend a further 90 million £ years later on to replace many of the working parts, after they contracted Heckler and Koch to find and deal with the inherent faults in it.

  • Cage

    I have an ar 180 with no firing pin, what can I use in it or where could I get one from?

Leave a Reply to Chuck Cancel reply





You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>