Photos of the bore don't really tell you much, but here is my tuppence worth.  The rifle's bore looked dark. It's anybody's guess what you would find when you started scrubbing.  And it may well never clean up.  Barrels like that sometimes shoot jacketed bullets pretty well, but rarely do well with cast bullets.

The carbine bore looked as if it had just been worn but was otherwise smooth.  Those often shoot reasonably well with oversize cast bullets. 

For cast bullets, try to find .311 (or larger) hard-cast gas check bullets already lubricated for starters.  .308s are apt to be a disappointment.  Look for something like Lyman 311284 or 311299.