Yeah if you can throw a comet 300' you should get at least an extra 50' out of a driver unless you have the nose way up. You should post a video in the critique section and see what people have to say.
I was in the same boat for a long time, throwing mids about as far as my drivers, and I'm not quite sure what did it for me, but a lot of things that I worked on last summer were:
trying to keep the nose down obviously
NOT trying to throw harder when I threw a driver, I didn't even really realize I was doing this until I read something about it on the board here
I was throwing a LOT of mids and putters and ended up trying to throw drivers the same way, on the same lines, which is way too high for a driver, unless you can get the nose way down, which obviously I wasn't doing.
I'm not claiming to be an expert or to throw really far or anything but having just gone through this last summer I thought I would post.
I would def post a video if you can though, I'm sure some of the guys on here could tell you right away what you need to do to fix this.
Anode | Comet | Axis |Vector | PPD | SPD | CPD