I live in alberta and we get some pretty big black bears and I would not hesitate on a 250yrd and under shot with a 243. People think bears are invincible. A well placed shot with a premium bullet accubond or tsx and you will be watching that bear roll around in a death moan. Up here people use anything from a 243 to a 458 lott and bigger. I wouldn't run out and buy a .243 for bears but if thats your gun and you can shoot it confidently then load some good bullets and get a rug.