re: Can 6mm chamber in a 243 barrel?

There was a guy that came in the local gunshop the other day, he had tried to chamber one 6.5 round, into the chamber of another type of 6.5 rifle. I guess he tried to use a hammer on the bolt handle to get it to chamber, because he broke the bolt handle off. He brought it in to see if it could be fixed and still had the round stuck in the gun.
The owner called him all kinds of stupid, got the round out, handed the gun back to him and told him to take it home and never touch another firearm.
what the hell, go ahead and try it.