Already having the donor barrel that you don't use would make the rechamber deal much cheaper. Of course you're not garanteed the gilt edge accuracy that a SSK barrel would have, but I think the chances of having a good shooter would still be in your favor. I have two SSK barrels, a 6.5 and a .309 that are both lazers and I stumbled accross both on the used market, but, I was extremly lucky. I've been watching for a similiar deal on a 375JDJ ever since with no luck and that was 20+ years ago. In your situation, I think I would go for the rechamber, but, I would have SSK do the rechamber. As you probably already know, they are the only ones who can give you a true 309JDJ.
FWIW I've gotten a S-14 375Win barrel that I'm seriously considering rechambering to 375JDJ.
Walt
