The Tom Hammernick shoestring and stopwatch (torsional pendulem principle) method that Rocketman referred to earlier first shows up in print (to my knowledge) in "Shotguns & Cartridges for Game and Clays" by Gough Thomas pages 161-164.
Gough Thomas Garwood, M.SC, C.ENG., F.I.C.E, F.I.E.E. He was a working "chartered civil engineer" (back cover bio) who had an interest in "things shotgun" and an ability to write. Glad I got the multiple copies (mine and gifts) of his books on eBay years ago as they have become very scarce and pricey.
On pages 161 - 164 GT discusses balance, Figure 82 shows the shoestring and stopwatch method, Moment of Inertia (MOI) and how to calculate it and in Tables 12 and 13 gives data on Best Guns and then Other Guns.
Rocketman's apparatus is a modernized tool to measure MOI and has value if you learn the comparative language. And as Rocketman clearly pointed his MOI figures are "data" just as LOP, DAC, & DAH are "data".
MOI is an academically interesting "nice to have" once you have the gun in hand and quantifies why one gun feels like a "bridge-timber" and another, a "wand". The only serious problem I see with this MOI data is that virtually NIL gun sellers have it for their guns on offer....and maybe the vendor thinks that's a good thing if he's trying to move a "bridge-timber".
My $0.02 FWIW.
Last edited by Ian Nixon; 05/24/07 08:33 PM.
