So i did some tinkering this morning.
Measured all my #2 shell holder and they are all within a half thousandth.
Took a thousands and a half off one with the mandrel and sandpaper trick. No joy.
Could not really determine a rub with the sharpie trick.
I annealed several cases and ran them through the die and that did the trick.
I suppose i should keep track of how many time i fire brass but i dont. Most of my brass is picked up at the range so new to me brass is added to the bin where i keep the 30-06 cases. so some may be once fired and some could be 3,4 5 or more times fired.
That would explain the random nature of cases not chambering sometimes but not all the time. so next time i have a bunch of empties i will setup and anneal them all to reset and then perhaps i will sort by times fired
Problem solved thanks for the help.