The barrel lining has become better over the years but is generally done to very old rifles that a virtually impossible to get new barrels for, especially if you want to retain the original profile and stamping marks. Having the liner epoxied in is cheaper than getting it, and the drilled barrel, tinned with silver solder. If properly done, the latter method is preferred by higher end gunsmiths. Although they shoot better than a rusted or worn out bore, the liners generally have shallower lands and grooves than the factory original bores. They are a bit more ammo sensitive to get decent accuracy.