I can't speak for the accuracy of the octagon bbl. But I have the 30-30 in a 10" bull bbl. I would not think that the weight difference would be that great between the two. My 2 cents worth, if a heavier bbl gave better accuracy that is what I would go with. If I do my part my 10" 30-30 is capable of minute of bowling pin grouping at 200 yards off the bench.