CrossRoads:
Sounds like its time to add a new tool to the tool kit
http://www.harborfreight.com/4-inch-digital-caliper-47256.html
Ha, I love Harbor Freight and there is one nearby and that is where I got my compressor and extra air tanks, but I have never considered them for precision tools.
I have found some headers that are 0.2" (5.08mm) by design and I think they take the heavier pins. I am going to try to sample a few and if they work I will buy some.
Going to see if they have these calipers at the local shop.