Dave Saxton wrote:This particular data set for the 16"/45 with 2700lb projectile does not plot as a curve. It's rather hurky jerky and then suddenly at 30,000 yards the plot turns into a virtual straight line going steeply up. Can't be right. No way. I don't want to put the public spot light on the compilers of the table though.
I can see the deck penetration coming out virtually the same for the 16"/45 with 2240lb projectile and 16"/50 with 2700lb projectile. The lighter projectile will have slightly less velocity by then but it will have a slightly steeper angle of fall at long ranges as the result of that.
..... Dave,
I plotted the USN Vpen, Hpen and the striking velocity computed by my external ballistics s/ware. They all display as smooth curves for me. The steep increase in the slope of the Hpen curve starting at about 30,000 yards corresponds to the increase in striking velocity due to gravity effect upon the falling projectile simultaneously with accelerated increas in angle of fall, so I'm not seeing anything unusual there. Exactly what data set is plotting badly for you?
One thing I did note is that the 16/45 ballistic data in Campbell are given in uneven increments - i.e.: 10,000, then 16,000 then 20,000, then 26,000 yards, etc. - making alternating increments of 6,000, 4,000, 6,000, etc. Might that be the culprit?
Byron
p.s. - You analysis of the Hpen of the 16/45 2240 lb projectile versus that of the 16/50 2700 lb projectile corresponds to the USN data given by Friedman - their plots are very close from 28,000 yards out.