I don't know Mr. Willis, and I stumbled on his website by accident while looking up the definition of "overall length" as to dovetail cutting bits for milling machines. I happened upon his discussion of OAL as it applies to reloading rifle ammo. I thought it was pretty informative, and he has an innovative product, so I thought I'd pass it on. Take a look, in particular, at his "tech tips" page about halfway down the menu on the left.
Daniel L. Hawes - 540 347 2430 - HTTP://www.VirginiaLegalDefense.com
By the way, nothing I say on this website as "user" should be taken as either advertising for attorney services or legal advice. Everyone having a question regarding the application of law to the facts of their situation should seek the advice of an attorney competent in the subject matter of the issues presented and licensed to practice in the relevant state.