[taylorce1]

You have a few options that you could do, but first thing I'd do is take the rifle to a gunsmith and have a chamber cast done. This way you'll know exactly what you have, and what is safe to shoot. My guess is you'll be able to shoot regular 7mm Remington Magnum ammunition out of it. Who knows you might get enough accuracy out of it to be happy with it as is.

1st option is get into reloading, my guess is it will cost you around $300 to get started if you have to buy all new equipment with custom dies. However, if your GGF built it your family may have the dies and other equipment already. I'd ask around with the other relatives who may of received some of his equipment and rifles.

2nd option while at the gunsmith ask about setting the barrel back and rechambering to 7mm Rem Mag. If he is able to do it it will cost around $350 on average. Not too terribly expensive and you can run factory ammunition and never have to worry about reloading if you don't want to.

3rd option is to rebarrel and the most expensive around $700 ballpark. You'll have to stick with a magnum cartridge and the 7mm Rem Mag or .300 Win Mag would be the most practical. It would require so much money to convert back to a .308 that you could probably buy at least two brand new rifles or one with a high end scope for what it would cost.