I was using a GI test bolt and 1.300" GI guage. They closed easy. Then I switched to his bolts and 1.300" guage.
I have read that GI field guages went up to 1.302". My Forster gauge set has 1.290", 1.295" and 1.299'. I think I will stick to 1.299" or less after seeing this. I don't know if the headspace has always been long or the receiver has lengthened.