Not necessarily. I have males that get up to a weight of 116 sometimes and they're not giants. It's a question of being from known giant lines. There is also a "giant" body type which I'm not familiar with because I don't work with giants.
Hmm ok thanks 100 g is still pretty big for the average leo I wonder if the size will be heriditary even though it's not the 'giant' gene. Is it so with your lines acpart? As in are the babies from your large males also pretty large when adults?
All my breeding males are large and the offspring run the entire gamut from really small to really large, so I can't really say whether or not it's hereditary.