Marvin, of course, is right. I am also sure Bob Werner wishes no one any ill will, but rather, is being quite frank and honest when he says that he will not be put in the position of endorsing or certifying any other tuners who may wish to step up and learn the business of tuning air rifles. To get to Bob Werner's level of expertise takes years of hands on experience. And along the way, reputation, good or otherwise, must be earned. It cannot be casually passed on by an online endorsement or by posting a "tuning tip of the day" on the GTA. No more than, for example, Marvin could teach someone like me to be a master machinist via email. Skill and reputation are earned by hard work and unfailing integrity. There are no shortcuts.