On at least two previous occasions I've posted links (one in response to "Captain Kirk" on the 'other board') to articles about the grain structure of electro-deposited copper. In short, electroformed copper has a very small grain size -- a characteristic of hard metals. Now, bending the bow (the U-turn) in a trumpet bell involves repeatedly annealing the metal -- creating large grain size and soft metal. And the heating involved in rolling around a wire and soldering a bell rim will also effect the small grain structure. So it's debatable whether Conn Coprion bells took complete advantage of the unique grain structure of the copper. But simply trimming the copper off at a set diameter won't heat the copper enough to soften it. I own a Conn cornet that Michael Del Quadro modified with a beadless copper bell, so I have some "owner's experience" with beadless copper bells from different sources. The bells on both the NYTC trumpet and the Del Quadro cornet were plenty hard, and neither seemed more fragile than a brass bell with a bead. I also own a Calicchio flugelhorn with a solid copper bell which was formed traditionally from copper sheet, and that bell is thick, heavy, and soft. I have to assume the thickness is in some degree to compensate for the softness, but the flugel bell has picked up dings much more easily then either electroformed bell. While I have no reservations about the strength of these bells, I do think taking full advantage of them involves experimentation and prototyping. The Magnum trumpet had no doubt gone through many iterations and design refinements to result in a horn that I really could have played to this day -- nobody ever said to me, "Dude, that trumpet just doesn't work for lead playing. Get something else or find a new band!" I simply found that *I* wanted something different, and a different trumpet that happened to have a bell with a bead delivered an indefinable difference I preferred. The Del Quadro-modified cornet is a unique beast that reveals its one-off roots: It plays great, I love playing it, but it only works in certain settings. It projects more like a flugelhorn -- the sound is diffuse and seems to project as much back as forward -- though it doesn't sound like a flugel. I really enjoy playing it in small venues, playing small-group jazz.