This was also posted in the build it yourself area.
I recently built two AK 74's from a kit. One had no issues with headspacing when the barrel was reinstalled. The other had a good headspace prior to removing the barrel in order to install the trunnion in the receiver, but had excessive headspace after the barrel was reinstalled and pin put back in. I put the rifle with the pinned barrel back into the press, and pressed the barrel further in, and it now has a proper headspace.
That being said, should I still be concerned and consider getting and installing an oversized barrel pin, or will the barrel remain in the proper position for the headspace and be good to go with the current barrel pin?
The headspace measurements were made using headspace gauges.