Match Grade .22 LR / AR-15 Fabrication
How a .22 LR Match upper is fabricated
It's journey from a raw blank to the winner's circle.




Because of the 1.170" diameter of the collar on a standard center fire barrel, a large enough barrel blank must be used in order to ensure the barrel is a monolithic construction and not made of multiple pieces.  Shown here is a 1.200" diameter rim fire barrel blank.


A cone must be turned into the face of the barrel in order to utilize a feed ramp, which is extremely important if the best possible reliable function is expected.
Once all of the metal is removed to expose what has been lying underneath the surface just waiting to be seen, we can see from this photo that all but part of the cone from the previous picture is left in order to form a cartridge feed ramp.  Also, strategically placed slots must be milled into the barrel shank in order to accommodate the extractor and guide rails.  These slots must be placed exactly right, or an ugly and sloppy finished product is a result.

It is also important that the locator pin at the top of the barrel is properly timed to the slots in order to achieve proper alignment  in the receiver and bolt lock up.



Once all of the machining over at the milling machine is completed, the barrel must have that ever important rim fire chamber cut into the rifling and feed ramp.  Once everything is properly indicated, the chamber is cut to the proper depth and the barrel is then ready for final clean up and further contouring to fit the end user's application.


As you can see here, the finished breech very closely matches the dimensions of the chamber adapter that comes with the conversion unit, which will be discarded.  In this picture, they are a mirror image of each other because the chamber adapter on the left is from a LH conversion unit, while the finished barrel is right handed.



Here is the finished product.  From this point, it can be made to fit virtually any AR-15 configuration, from a pistol, to a match or NM service rifle training upper, or even a full auto carbine.  Yes, they are that reliable!