513t Loose Barrel

Just recently dragged out a 513T I purchased through the CMP. I never noticed before as I haven't shot the thing, but, the barrel has some (maybe 5 to 10 degrees) rotational "slop". I took the action out of the stock and the two pins holding the barrel to the reciever seem plenty tight. I'm wondering if there's an approved tightening method or should I peen or shim what looks like a key or dovetail on the bottom of the barrel. This is the first time I've had one of these apart and I'd like to fix it correctly myself. I've searched here and a few other sites with no results, even checked out the G.I. technical manual. So what's the deal?

Odd problem w/ several solutions. First thing, I think, would be to pull the barrel, and see what is the actual cause of your problem. Then it might be easier to figure out a good course of action.

Detailed pictures of any obvious dramas would be good too, but it may be something too small to show. Have you tools and precision measuring devices?

BTW, Welcome! Feel free to post whatever info you discover.