I did consider a trunion jig but I am too cheap. By the time I buy all the jigs and so forth I might as well buy another AK. However I found a plastic jig made by Childers that you use a marking punch, probably wrong name, mark the holes and drill them out. I now have all the parts and am getting ready to build. Just not sure how I will accurately place the lower rails.
5/32 is the size for the rivets. And you need a transfer punch and Childers sells those too. And AK builders has a rail alignment tool and you will need a 5mm and 7mm reamer for the axis pin holes once you get them drilled.
Yes, a transfer punch, that's what I was thinking of. Got one already. Thank you for the other info as well, it will help to have advice from others who have already done this.
How did you attach your rails? Did you spot weld them. screw them, or braze them in place?
I haven't attached mine yet I've got to get the scale cleaned off of them first before I spot weld them. But you can spot weld them, rivet them, braze them in or plug weld them in once you get them in the correct position. If you were in michigan and traveled to Alpena I can show you how to do it I even have a Trunnion drilling jig and a receiver drilling jig.
I believe this is what your trying to achieve right?

This is a AK-74 blank that I drilled.
But do the rails last you need to insert the trunnion and get it's position set with a 7.62x39 AK magazine.