I am with the popular opinoin on this one. Have used the .270 my entire life on game from foxes to Canadian caribou without a problem. Shot placement is important when taking any game no matter the caliber so I wouldn't heavily weigh that factor. Never taken Polar Bear with it but have taken many Black Bear weighing in the 200 - 300 pound range. There are also now many more bullet options out there for the .270 (.277) now a days for the reloader. Unless you are looking for something extremely exotic the bullet is out there in .277. The round is popular enough that bullet selection is almost on par with the 7mm / .280 bullets. Good luck.