Okay, So, if it is advantageous to reverse the leadpipe.., then can I cheat, and simply reach into the existing leadpipe with a narrow roundfile, and acheive simiar results?? This is a "B USA" trumpet and it has a great sound for a beginner trumpet, but it has a flat spot when trying to get above the staff. When it is not yet warmed up.., I almost always cannot get an F right away, and it falls off unless I force it. I think it is an airflow restriction?? Anything above that, and it is OK. maybe it is #1 valve problem?? I do not want to ruin this horn. Although it is a cheap horn, it looks and sounds GREAT!! What can I do to improve lead pipe, without reversing it?? Can I reach in and file it W/out causing it to sound too flat or sharp?? Also, I was thinking maybe if a file cannot round it, I can try a tapered grinding tip, like from a dremel tool, and lengthen it's shaft to reach into there.??