Mauser right design and construction of the bullet produces the difference in results some are expansion design and others are made to retain weight for increased penetration design. Lots of overlap as well for deer bullets but that is why we pick the one the rings our fancy!
shooting a 300lb canadian whitetail id definently take a bullet designed to hold up to the task......all bullets are not created equal
NBT's are all I use for our whitetails and never had a problem dropping the canadian prairie bucks with them. The real qualifier is distance and where you aim! Many guys who come up here to hunt aim for the high shoulder shot so they prefer nosler partition, TBBC, etc. However if your shooting ribs the NBT blows right through the same on 300 lbs buck as it does on 175 doe. The NBT is a great boiler room bullet IMHO comes with superb accuracy, excellent for down range shooting ability and puts a good wound channel in the animal.