load them near max and put the choice of bullet into the lands.this will blow the case out to the ackley chamber.just make sure the bullet is in the lands.this pushes the case into the bolt face letting the pressure inside of the case before the bullet leaves the barrel blow the case out.heck you might just end up with a good fire forming load while doing this.or at least most of the time I should say you end up with great accuracy while fireforming a case to an ackley.