If you have an older BT-99, they had an ejector. New BT-99's have an extractor. If you have an older ejector model it could have been altered to simply lift/extract the shell.
That I don't know. Search for a schematic on the internet of an old BT-99 and a new one and see what components in the forend are missing. Or, contact Browning.
I have a BT 99 that ejects them and while it's nice, I really think it's more of a pain. I reload so I don't want my shells hitting the ground and catching them as they come launching out of the gun is the pain part. I really would rather just pull them out.
Some of this years 99s come with an ejector (guns unlimited was selling them at the grand -- see their web site). I like extractor only.
I like my ejectors- largely for novelty though (it is always fun to see new shooter's eyes pop when I shank the shells and catch them in my shooting pouch. It is a useless talent have gotten down to a science). Every now and then, I catch them in my hat (although I am still working on getting that down to precise consistency on that one). Still, there are times when I do not want to use the ejector function. Like tangy033, I too reload, and hate the thought of my AA's or STS's hitting the ground. Besides that, it is poor etiquette to leave spent shells lying around for someone else to have to pick up. Simply "extracting" is so much easier than having to bend over to retrieve my shells. I just open the breech enough to pull the shells out, just before the ejector hits and pops the shell.
My 99 ejected them and I did not like that so got to looking and their is a rod that goes to the front of the receiver that I took out now it just lifts them. I put the rod in the hole in the back of the stock incase some one else wants it to eject.