GSY - it would be "Blastoff!" I shoot a variety of guns. I adapt to differing stock dimensions, to differing handling dimensions and to differing aesthetic stimuli. I am currently logging the results of shooting these differing guns. Stock dimensions are, of course, easy to measure (there goes that 'ole yardstick). Handling, to me anyway, is easy to measure. Aesthetics is still a mystery, but I know it is there. The good news is that I can easily share results that include stock dimensions and handling dimensions. Handling will not depend on my subjective judgement of the guns, rather it will be objective data for one and all.
JH - the gun will swing naturally about the balance point (center of gravity/CG/teeter totter point) unless some effort is expened to force it to do otherwise. The lowest swing effort will always be about the balance point. Shooters with differing prefered hand spread and differing physiques may well swing the gun differently, but the characteristic of the gun itself is at the balance point.
Mounted swing is calculated (from LOP, weight, and MOI at balance point) for the butt. I agree that the true axis is somewhere within the shooter's body, but we do get a useful characteristic by this calculation. BTW, this calculation is based on the parallel axis theorum which says we can calculate MOI about any axis.
Balance can be referenced to any point you choose. The (front) triggger is the mose useful and simplest. Balance tells you how the weight of the gun is proportioned between your two hands. Your back hand is always positioned to pull the trigger. So, we know the dimensional relationship between your back hand and the gun. Measure your personally prefered hand spread and you have all the information needed to calculate weight proportioning. Any other reference point will involve more measurements. Since hinge pin to hand and breech face to hand are not fixed, comparing guns becomes more difficult if they are used for the reference.
Half Weight Radius is simply a numerical statement of compactness. 10 to 11 is pretty average for most guns. Under 10 is more compact weight and over 11 is pretty dispersed weight. Direct comparisons require the guns' weight be similar. HWR has no value in telling you where to place your hands - do what you feel is natural for you or what a coach tells you.
The Ruger GL got its handling from referncing the handling properties of a Dixon RA, including MOI. Many gunmakers do MOI intuitively. Some are starting to pay attention to the possibilities of owner adjusted handling.
Cadet - I believe in magic. But, like the Conn Yankee of Mark Twain's imigination, some magic takes a little preparation. IMO, the magic happens when a shooter finds/has made a gun with accurate fit to his stock dimensions, handling properties that suit him best, and aesthetics that really hit his hot button.
DM - my life is very, very real. This is some of what I do for fun. I can measure to any required accuracy. However, I actually measure to those accuracies that are practical for this project. Parts of my database are published and other parts will be. At this point, it is a freebie for those interested.
DS - did I forget to mentiion this cutie is a 20 bore/gage/gauge/guage??
And, thanks to many for their kind words and support.
