Had some build time this weekend, and finished a long anticipated project of mine. This is a Saiga 20 converted to an underfolder.
In the end the conversion was easier that I thought, but I do have the right tools now. I used a mill to get rid of all the rivets on the factory rear trunnion and on the scope rail. I used a polish made rear underfolder trunnion, it lined up perfectly with the receiver and the long rivet hole. The Yugo M92 trunnion I tried before did not line up.
I used a HF TIG to weld up all the holes, except for the long rivet hole. The remaining rivet holes for the rear trunnion were then drilled and the trunnion was used to scribe the UF pivot hole layout.
I then riveted the trunnion in place and milled out the underfolder pivot holes. I made them undersized and then filed for a precise fit with my stock, no wobble at all. I used an 11/16 HSS mill bit for the large hole.
All that is left now is to bead blast, park and duracoat.
Any suggestions on how to smooth out the weld bead on the closed holes.