You can find plenty of small labs from "field lines" that are 45-50lbs. My female lab is about 45lbs.
I have to agree with this and nothing against the boykin owners but I have seen quite a few boykins in the less than a year I have been in the hunt test world and their water attitude is just not the same as the labs I have watched. here is an example midlands test watched 20 labs run a finished test and the test was running right around 12 mins the one boykin that ran took almost 20mins and this was in a stick pond with fairly short marks (longest being around 100yrds) also I marshaled started on Sunday and there were 18 dogs and 10-12 were boykins the rest were labs and 1 poodle the labs went flying off the shore for each mark only about 3-4 boykins hit the water as hard as the labs. I say this saying not all labs hit the water hard either but just my observation from watching tests for the last spring and fall. will say you put a boykin on land and you will have a little brown dog that is a rocket and will not slow down until it finds a bird.
also nothing against the boykins but just wanted to state my observations.