While another thread is discussing choke modifications, I am stuck here wondering why different barrels from the same manufacturer exhibit different profiles. In the years that I have been measuring chokes (in older guns) I have gotten to the point where can I recognize some generalities of choke profile characteristics from some makers, but as of yet I have not seen identical profiles for two identically marked constrictions (i.e., full and full, same maker). Each seems to have been a piece of work unto its own. Any insight or comments?