new 450 marlin barrel for my TC

[LaMott Cowan]

 hey guys i got a 450 marlin barrel for my thompson center for x-mas. any suggestions for a good distance & load for sighting it in. the barrel is 24" long w/ a military 50cal. style muzzle break. Im looking to get a good distance with this heavy round but still have the knock down power to stop a bear. what do ya'll know about this round.