I think almost any of the more powerful rifles are capable of putting down a pig given the right circumstances. I would think a shot placed in the temple, eye or ear might do it in one shot for the condor and the like. Some of the less powerful guns could do it with multiple shots, it just depends on how far you feel like tracking the prey, and how much hurt you want to inflict. There are folks that do it with bows routinely. Personally, if boar was ever my choice of prey again, I'd want all the power I could get, .30 cal. at least. I've seen first-hand how p'd-off a boar with a misplaced arrow in him can get. The darn thing "tree'd" three of us in about 5 sec. flat! Took two more arrows to lay him down and another to put the lights out. As far as the newbees, there really isn't much you can do. There will always be newbees who will get into new things without doing the proper research. There really doesn't seem to be anything( in my experience) that you can do for them. The youngsters will hopefully learn a few hard lessons early on and be the better for it. Others are destined to make the same mistakes over and over, and never see the light of day. pv
If I remember right the 30-30 has more energy at 100 yards than the .44 magnum has at the muzzle. Factory loads not handloads.