I'm not sure there is a sure fire way to discern a male from a female. Our regs state we can't shoot a female with cubs visible. I don't think young boar is going to look different than a sow. Your .243 is adequate for black bear within a couple of hundred yards. As in all things, be sure on shot placement. If your shooting long distances, like some areas out west, there will be less kinetic energy down range than with larger calibers. That could be key on a large bear...