chk, Ackley was correct. Much of what we shoot today in bottle neck cases today, are " overbored " It's all boils down to expansion ratio. The case capacity/bore dia... A longer barrel, nets you a higher ER, thus more velocity out a given case and bore. Personally I wouldn't rechamber a 22" barrel. And most likely isn't needed out to 300yds. And a 24" is as short as I would shoot in AI, 35 cal. and under.