Here are some lead bullet .348 Win loads from the Lyman cast bullet handbook:

187 grain lead bullet #350447 (.348" dia.)
2400 20-23 grains, 1610-1779 ft/sec
4227 20-30.5 grains 1510-2123 ft/sec
4198 25-35 grains 1672-2150 ft/sec
3031 35-47 grains 1818-2338 ft/sec

255 grain lead bullet #350482 (.348" dia.)
2400 19-22 grains 1412-1560 ft/sec
4227 21-30 grains 1428-1838 ft/sec
4198 27-38.5 grains 1661-2096 ft/sec
3031 35-46 grains 1798-2217 ft/sec

There are several internet sources for .348 lead and jacketed bullets and also brass. Winchester still lists .348 Win unprimed brass as available, and there is usually some fired brass listed on Gun Broker. If you plan to shoot much, going into reloading in a modest way will be worthwhile. .348 loaded ammunition is difficult to find and is expensive. I don't think any of the big guys (Federal, W-W, R-P) still load it.