There are two sizes to the old feed elbows (well, 4 actually, but 2 are a bit rare). 7/8" which was more common on newer style guns, and 1" which was more common on older guns. The Raptor uses the older style 1" feed elbows. They're more rare these days, but you can still find them. If it doesn't say 1" in the description then what you're looking at is a 7/8" elbow, so don't buy it (well, at least for a Raptor).
Allen Paintball Products still stocks the 1" elbows new....
http://www.allenpaintball.com/retailframeset.html
...look under "miscellaneous". They're cheap, so buy a couple.