Well, if you've done any looking for BB on the Web before, I'm sure you already know about Yoda and his forums. But if you don't, the current URL is
http://bbgroups.tlcnet.com/
Unfortunately, I haven't checked out the forum since the switch to DBabble, so I can't comment on its current state. From past experience, there will be new stories and reposts of some old ones, but with every transition to new board software a lot of old stuff gets lost.
Takethepitch.com might have been what you were looking for, but unfortunately that site looks like it is gone. It was based on a guy's personal collection, so it was nowhere near as extensive as this archive, but it had many stories.
Note that many stories on both those sites involved nullification, so you wouldn't avoid the genre entirely there. Like you, I don't like castration myself, and I'm here looking for stories I can mentally "rewrite" more to my liking.
I am sure you also already know about the Diana the Valkyrie site, which has stories from several femdom-type genres. Some of the authors with BB include BOS, Hardie (though it seems more and more sadism is creeping into his stories), Counselor, A-Man (sadism in some stories), Marot, and MBP (mostly armwrestling and "magical" strength, but his BB stories are classics).
http://www.thevalkyrie.com/library.html
One guy has a couple of his stories at
http://bustednuts.mysitespace.com/
Also, you might want to check what you can salvage from old sites at the Internet Archive.
Some BB sites to check out for links:
MatRat 60 at
http://www.oahukane.com/
Scrambled Eggs at
http://www.callnetuk.com/home/busted/index.htm
Well, that's all for now. I hope I've told you something you didn't already know!