PaulS, I assume you mean changing my mind on the chambering. The biggest factor in that change was after emailing Dave Davison from CH4D, about dies. He ask me why the 280 Ackley case. I told him the reason was an increase in case capacity over the 35 Whelen Ackley. The next day he replied back and said he had ran some calculations in his Accuload program and that according to the program the increace in capacity would be about .3 grains of water, or .006 cubic inches, for an aprox. gain of 1 grain of powder. The program showed a 36 fps. gain in velocity. That is less than I would have thought it would be just by looking at the cartridge drawings in the manuals. The difference in the cost of dies did not matter that much since it would be a one time purchase but the added time of case forming for 36 fps I decided was not worth it. I know that I have to fire form either one but I wont have to neck the brass up first and if I had to I could shoot factory 35 Whelen ammo.
I changed my mind about the contour of the barrel after the gunsmith said that a #3 would be fairly light in a 35 cal. and he suggested the #4.
BruceP