I use the RCBS tool a lot I have found that a dollop of case lube on the swage every once in awhile tames the pressures down a lot. My next question is if the cases are new and unfired then there should be no swage to have to remove. I fired a lot of LC Match and never had any that were swaged and used them for reloading all the time. Machine gun ball was an entirely different story.
Used to pick them up off the bore sighting pad for UH-1C/M and AH1 helicopters all the time. Machine gun ammo was expendable while Match ammo had to be turned back in. It was all done by weight not head stamp.