We raised BBB's one year, let them grow about 8 months. They were HUGE, some over 60 lbs. We cut them in half lengthwise, and roasted half at a time. I have a really big roaster, had to cram them into the pan. I remembered my folks splitting the turkeys like that, now I know why.
The next year, we got hatching eggs from McMurray, Narragansetts and Bourbon Reds. They dress out around 30-40 lbs, at about 8 months. The breasts weren't nearly as big, but the taste, probably the best I've ever had. They had to roast longer to get tender, but they finally did, and they weren't dry at all. Even the breast. I did baste a lot, but I'm gonna try that cheesecloth, Miss Prissy! That sounds a lot easier than what I've done before, a couple of times. That was to roast the bird breast down, like Acre of Blessings suggested, but when the bird was about done, I wanted to turn it breast up so the skin would brown and crisp. It's really hard to turn over a big, juicy, roasted bird. Plus some of the skin stuck to the bottom of the pan and tore off when we turned the thing over.