I noticed that too. I've had Tyson for about 15 months and he's gained less than 700 grams. He's not much over 800 grams now. He eats every week, well almost, he IS a BP after all...
He's on small rats weekly, but the largest of the last order I placed. I'm getting some mediums within a few weeks. I'm curious to see if he hits a growth spurt like he did when I switched him to rats...
But anyway, OP, that seems like some pretty quick growth. What are you feeding and how often? In your thread you said she took another large...large rat?