Ottawa;
I've hand tapered and flared a number of barrels, and it's not that hard to do. I would not taper this one more than a sixteenth inch or so - down to 13/16th. Instant blue the barrel, use a sharp scribe and a straight edge and mark the first four opposing flats on their adjacent flats, then use a grinder and take down the first four flats to final dimension, stopping often to cool the barrel with water. work opposite flats, and go fairly slow. True up the first four flats with a mill file. Then blue those flats, and scribe them, then grind the final four flats. It takes a bit of time but is pretty easy. Hope this makes sense.