# SA-UCA-01 For standard square rear trunnion AK pistols like Draco
# SA-UCA-02 For angled rear trunnions on Yugo M92/M85 AK pistols
|-The rear trunnion needs to be drilled and tapped using a #21(.159)drill
and 10-32 tap(spiral point tap preferred)
-The holes are .625 center to center
-The position of the hole pattern is .875 from the bottom edge of the receiver to the center of the holes.
-Once the hole locations are marked use a center punch to indent the
-Use a spot or center drill to make divots which help keep the #21 drill
-Drill the holes with a #21 drill, some people start with a smaller
drill and then follow with the #21
-Tap the holes with the 10-32 tap, a high quality tap makes a big
difference in the operation, we use Cleveland brand but there are plenty of good brands.
-Use go slow and use cutting oil on all drill and tap operations.
If you don’t want to tap the trunnion you can just use a larger drill bit that will let the screws pass through and use our AK Pistol Tapped Block which fits inside the receiver