Question for the Bravos ....

[Sdiver]

Now don't all stampede over yourselves answering this question .. "Oh, I know, I know, I know !!!!", so here goes ....

Have a friend who found an M1 Garand for a nice price, but it's a .308
I told him to get it, but if he does, we wouldn't be able to share clips (mine's a 30.06)
He said that, that shouldn't be a problem. That a 30.06 should be able to fire down a .308.

Now I'm only a medic and don't really know bang-bang stuff, but with my limited thinking on this, I would think that it wouldn't be possible. The .308 if fired down a 30.06 would be too big and get stuck, causing a "weapon malfunction", where as a 30.06 fired down a .308 would be too loose and not fly straight and narrow.

So, answer away. Is it possible to fire the different calibers down the different weapons, or is it a recipe for disaster?