I made one of these yesterday and used it to do the front trunion holes on my AMD-65... This tool was simply awsome!!! I managed to find a set of tweezers with a wide and flat "pinch" surface... that was the hardest part of making these....
Then I took a piece of scrap steel that I had that was about the diameter of the tweezers and placed it between the two tongs of the tweezer for spacing and drilled a hole through the on the trill press. I used a #29 drill but as I had the 8-32 tap and plenty of 8-32 screws.
Next I checked the tweezers and when they wre pinched closed the holes were perectly aligned so I pinched the tweezers into the vise and tapped the holes 8-32 and screwed in a 8-32 x 3/8 button head screw....
I had all six of my front trunion holes center punched on my receiver in less than a minute... this is THE WAY to do front trunion holes when you have the barrel pulled.
Now I need to see how this can be done with the rear trunion holds
I have pics and I will try to post a link when I get time to get my pics cut down plus I have server space issues as I have about 700MB of photos on my current build so far... I need to get rid of some and cut them down but I want to keep building when I get a few free hours too...