LOL all entertaining answers thanks for participating. The reason given to me by my buddy was that when he does his resizing he puts a bit of case lube inside the neck before sizing, the lube acts like lube for a while then , after a few years , it gives up acting like lube and dries out and acts like glue. "glube". It glues the bullet to the neck. When the shot is fired, the bullet takes the neck with it for a while, and leaves the neck in the lands.
He loaded this ammo 8 years ago. He uses the oil lube, not the dry lube.
The solution is to dry the neck out after sizing before loading, or use a different lube, or shoot your ammo quicker, he owns too many guns so only gets to shoot this one every few years, so he should consider owning less guns.
If you suspect you might have this problem then just put them all back in the press and seat the bullet by a thou. sure you will increase the jump a bit but it breaks the grip of the glube.
The puzzling thing for me, is my friend seemed to know all of this, he knew exactly what happened and why and how to fix it, and yet he still arrived at the range day without taking any remedial action. Maybe he was just trying to give us all an object lesson!