I have gotten many PM’s both here and on other sites asking how I installed the folding stock on my SBR’d Draco pistol. Below are the steps I followed. Keep in mind, I did everything with hand tools (including drilling the receiver). If I were to do it again, I would either 1) send it to a gunsmith or 2) track down someone with a drill press.
Essentially what I did was this:
1) Line up the folding block on the rear trunnion and mark the mounting holes with a sliver Sharpie (the folding block has slots, so the holes don't have to be aligned perfectly even though I tried and failed)
2) Drill and tap the holes (I can't remember the bolt size I used, but I believe it was 10-24)
3) Align the folding block to the rear trunnion and place a locknut on the inside of the receiver (I used the closed end of a combination wrench to hold it in place)
4) Apply red loctite to one bolt and thread through the receiver, capturing the bolt with the lock nut
5) Repeat with the other bolt and nut
6) Attach the stock to the folding block
Misaligned bolts
Minimal intrusion into the receiver (actually had the camera slightly forward so that the nuts would be visible)
Folded length with YHM flash hider (Phantom for use with a 7.62 QD can)
Final product: