Rocketman, does length have any real affect on the MOI versus the weight of the barrels and the affect of length acting on the point of balance as a lever?
Yes, it does. Balance is the zero summation of increments of length times the weight within each increment. MOI, on the other hand, is a total summation of the weight within each increment times the length increment squared. A lot of difference!
That is, would the MOI be different for barrels of different lengths if the point of balance and the weight were the same?
Most likely the MOI's would differ, but not absolutely. That is to say, a gun could be made with interchangable barrels of differing length, but common weight, balance, and MOI. This would require the gunmaker to have a design that took MOI into account and for him to measure the MOI during fabrication; just as weight and balance are frequently measured and compared to a target during fininshing of a gun.
My high school physics tells me that with the exception of the slight difference in resistance through the air that it is the mass of the barrels forward of the point of balance that is the major factor.
You are certainly on the right track. However, if mass is added to the front of the gun, one must consider the weight increase and balance shift forward as the MOI number will be for the whole gun. I love it when someone starts thinking physics in this issue!! Keep it up. I'll be happy to coach and explain until everyone interested gets it.
