i do not know a way that you can do the rechamber. when a barrel is chambered for the ai cartridges it normally has to be set back. the headspace is set so that the standard cartridge go-gauge becomes the ackley no-go gauge. the standard cartridge needs a crush fit in the ackley chamber to establish headspace. to run an ackley reamer in the barrel and open up the chamber with its current headspace will not give you a true ackley chamber. it may give you a larger chamber that you can make cartridges for but it won't be an ackley chamber.