Curious what bullets you were using on the pigs in the .243/6 mm or 6.5 caliber you were using? I believe either caliber with the correct bullet would handily do the job. Either caliber in the heavier grain for caliber bullets have good sectional density and will penetrate fine if the correct bullet is used such that it doesn't fragment. While I have not shot any pigs, but having grown up on a Montana ranch, I have shot a number of elk and most with a .25-06 and some with a 6 mm Remington. Mostly one shot kills.