Then there was the guy who brought a rifle into my shop back in the 80's. He came from the range. He said he fired one shot and couldn't get the bolt open. When he started beating on the bolt handle it came off.

Yep Remington 700.

I contacted a Remington warranty center (Huntington's) and asked their thought's and direction. They said pull the barrel and make sure the gun was unloaded. Then send the gun to them for reassembly. They suspected a 7 MM Express cartridge had been fired in the 7MM Mag Chamber.

That is is indeed what I found when I pulled the barrel. The surrounded bolt head held the pressures, but the cartridge ruptured. Fragments had jammed the bolt closed.

Huntington's did the repairs under warranty because the gun was new and the bolt handle came off.

I held a shop training session as the man had bought the rifle and ammunition from us. The Clerk who sold him the 7MM Mag rifle also sold him the 7 MM Express ammo at the same time. The Clerk did not know the difference.

Always wanted to build me a .280 Remington, but never got around to it.