Mine is a large bore, too, with a gold brass bell. It is very tiring to play above the staff for some reason (I have other cornets that aren't). I've had the valves aligned, which helped a little. The gap was huge, so I had the receiver reamed a bit, and that helped also, but I'm still not satisfied. I have a Mt. Vernon 106 leadpipe I'm considering having installed to see if that helps any. I've tried it zip-tied to the 184 pipe, but it's hard to tell much that way.