I suspect that the 60-grain Nosler Partition, for one .224 bullet, tend to fill in the grooves, because the exposed rear core tends to allow the expanding powder gas to "bump up" the bullet. Partly I suspect this because it was one of the most accurate bullets in my last .22 HP--and have also had Partitions shoot well in other over-sized barrels, such as the 180 and 220 Partitions in some (not all) .303 British rifles.
As for increasing erosion, that would also depend on how much you shot the rifle.
