Steve,
I pointed out in a previous post that one must account for bbl length. Owning chronograph(s) for almost 40 years one of the first lessons I learned was about bbl length and velocity. Most manuals do list bbl length and some manual list the bbl manufacturer. Some manuals discuss their methods and equipment used.
I also learned that with various loads sometimes increases in powder when nearing max charge can result in little or no increase in velocity or vice versa. In my 243's I see a fair amount of change in velocity with seating depth of the bullet. That is also where a chrono comes in real handy. If I'm seeing max velocity with a load and want to seat the bullet closer to the lands, I take that into account and may decrease powder charge a couple tenths or so.
A chrono isn't a replacement for a pressure receiver and bbl, but it is a useful tool for a handloader.
I'm glad that you accept it's a tool. It will never replace common sense and knowledge. I will say this to you, and others in this thread. Some of you kept saying "I know...". This is not a swipe at you personally a/c, or anyone else who has responded. The manuals were not printed for you personally, but the general public. You might know what you are doing, but the companies don't know you. You shouldn't assume that others will take your advice and use it properly either.
When I was in the military, I worked for a man who used to smoke in the explosives storage area, That was where we kept propellants, and other explosive types. He broke the rules, and was caught twice, but always said, "I know the dangers and know what I am doing. I only smoke in empty bldgs." Until he caused a fire in the compound. Low explosive powder dust was on the floor when he put out his cigarette. Two lessons were learned. Housekeeping and stupidity.
![[Linked Image from i.imgur.com]](https://i.imgur.com/AP39Jhm.jpg)
