Counter
5.56 Pistol build
  This build will be a lot more difficult than a regular AK build because it is a set of
new never assembled parts. It will require locating and fitting all the parts to the barrel
and drilling the pin holes. The slot for the hand guard retainer needs to be cut and the
barrel needs to be fitted and headspaced to the trunnion. In addition, the trunnion
needs to have .040" removed from the barrel hole and the barrel pin hole needs to be
drilled and reamed.
  I have never done this before so it will be a learning process with no room for error
as the parts are expensive. Once the current supply of kits with barrels is exhausted
this will be way you will have to do a build.
  I will be doing the build on an OOW AK 74 5.45 x 39 receiver as there is no 5.56
receivers available at this time. The only other receiver option is to use NDS AK74
receiver, the only advantage being they will custom mark it with the correct caliber.
Since both receivers will more than likely need to have the ejector extended I will go
with the OOW and have it engraved with the correct caliber designation.
  A proper size metric reamer will be needed for the barrel pin hole and a few metric
drills for the other pins. I plan on making a block to clamp onto the barrel to use a drill
to cut the hand guard retainer slot, and an adjustable reamer should do the trick to
open up the trunion.
Reaming the trunnion:
   
The barrel measures .907" and the trunnion .872", I have measured a couple
other trunnions / barrels and the interference is about .005", so .035" will need to be
removed. I used an expandable reamer to get it to within .002" and polished the rest
out with a brake cylinder hone.