Jake - I have devised and built a simple little machine that "spins" the gun on a horizontal turntable for one timed revolution under constant torque (bob weight drive with the drive line on the turntable perimeter). Moment of inertia is easily calculated from known torque (bob weight's weight times turntable radius), known angular movement (one revolution) and known time (stopwatch). Calibration is done with an assortment of steel and aluminum bars of measured size and calculated MOI; my cal is pretty acurate (R squared of 0.9998 for those interested in such things).
I multiply the actual MOI times ten to get typically whole numbers and decimals for guns and call it swing effort. There are other ways. Actually, Tom Hammernick showed that you could get useful data with a shoestring and a stopwatch (torsional penduleum principle).
I have a database with 386 guns (as of this afternoon) that I share with anyone interested. Anyone wishing to do his own work can contact me for assistance. I have built 6 machines (2 loaners). See Sept-oct 2001 Shooting Sportsman for an article on this.
BTW - I have gotten a lot more knots on my head than gold stars over this subject. Fortunately, I have a very hard head and thick skin. Questions are always welcome.
That Churchill was one of those guns that just screams, "Buy me, buy me!! I'm so cute you must buy me!" But, i know better!! An unmounted swing of 1.2 is about my legal limit for either fun or good shooting. I don't need one more gun I can't shoot well, no matter how cute. After all, I keep reminding myself that I can't afford to run a gun museum. But, it sure was cute, tucked into a deminuitive toe-under case that just fit
