Thanks Skip, we try. Good eye, Zulu! Can't remember if we told Gary about this Krupp tube. Double D., Come on, is that what you really think? You know the calculating duo better than that! Gaskill is on top of it once again. Gun tube #25 was a little short with the apologies of the steel yard bandsaw operator. Actually he did an exceptional job and got us 24 to spec. out of a 20 foot long, 2.5" dia. round of cold rolled, 1018 steel. I figured that we would get 23 good pcs. with the saw kerf, bandsaw inaccuracies, etc. This long, thick muzzle gun was an experimental tube we used to overcome the balance problems of proto #2. Proto #2 was muzzle light and begged for the hold down effect of capsquares, but capsquares were not in the budget, so another solution had to be found for the floating tube effect at near maximum elevation.
We thought that we needed more weight up front, so we conducted several experiments with proto #2 and the 25th tube, the .25" short one. First we clamped one little 2" Kant-Twist Klamp on proto#2 near the muzzle face, then ran the tube through all angles of elevation. She still floated up out of the trunnion cradles just a little. Another Kant-Twist Klamp was added just behind the first. Now we had enough weight; the tube had no tendency to float now, even at max elevation. So, after first weighing the two Klamps, an extensive weighing exercise began. Every cylinder on the whole tube was weighed, or rather, calculated, a full two pages of notes worth. All voids were calculated for their weight too, and placed in the minus column.
A determination was made that extra thickness up front could be had by re-dimensioning the whole built-up hoop configuration which was done. All bands were a little thicker up front, but even that wasn't enough when the breech lengthening to make more room for projectile loading was considered. It added almost as much as we had just made up for. The trunnion shifting and balance experiments followed and went on into the next day. Finally we had a number. Move trunnions to the rear .170" and proper balance will be achieved, we calculated. It worked and the First Edition Proto #3 was created with about 40 different dimensional changes and many different improvements including the anti-float, tube balance improvement.
That's about it.
Mike and Tracy
