Accuracy wise, ranges above 27,000 meters was less than 5%. This accuracy issue related to practical mechanics of manufacturing of the cannons, shell, powder and the physical mounting of the canons in relationship to each other ( interference ). Highly accurate sights and radar would not have helped all that much unless you add more cannons to the equation.
When you look into art of range charts and predicted ranges and variations you realize quite quickly how unpredictable results can get.
Using modern external ballistic programmes, you actually end up with more questions than answers.
One such extra question I have is the long range shots with elevations between 30 to 55 degrees.
What I found was the historical charts show the expected decrease in striking velocity with increases in range then an increase occurs at elevations mentioned. My argument against this is as follows ( I included a chart example with variations shown )
Comparison range chart between officially published values [o p v ]and ballistic computer results.
range chart USA 40.6/50 mk 7 canon with 2,700 lbs. (1,224.5 kg) AP Mark 8 muzzle velocity of 2,500 fps
Range -- Angle of Fall /o p v --Striking Velocity /o p v -- Time of flight/o p v -- elevation/o p v
10,000 yards -- 5.23 / 5.7 -- 2012 / 2,074 fps -- 13.3/13.2 -- 4.66
15,000 yards -- 9.46 / 9.8 -- 1789 / 1,892 fps -- 21.2/np -- 7.82
20,000 yards -- 14.99/ 14.9 -- 1581 / 1,740 fps -- 30.2/29.6 -- 11.4 /17,650yds@10degs
25,000 yards-- 21.99 / 21.1 -- 1388 / 1,632 fps -- 40.3/np -- 15.72 / 23,900ys@15degs
30,000 yards--30.15/ 28.25 -- 1210 / 1,567 fps -- 51.8 /50.3 -- 20.6 / 29,000yds@20degs (most accurate of comparison)
35,000 yards -- 40.22/ 36.0 -- 1043 / 1,556 fps -- 65.8/np -- 26.46 / 33,300yds@25degs
40,000 yards -- 50.18 / 45.47 -- 962 / 1,607 fps -- 80.8/80.0 -- 32.66
42,345 yards --53.92 / 53.25 -- 931 / 1,686 fps -- 88.2/np -- 35.65 / 39,500yds@35degs
np= not published
Except for a noticeable strike velocity difference most values are within acceptable tolerances.
Now while the explanation as to why at certain barrel elevation above 30 degs will travel further down range than otherwise indicated in a vacuum(45 deg is max range in vacuum) is logically acceptable. The reason being the reduced air pressure at altitude reduces the drag experienced while at that altitude which reduces the rate of reduction in velocity for that time period only. The shell still has to experience the same amount of drag on decent at any given altitude. Even in a vacuum the shell would still experience the effects of gravity (hence the curved flight path) any increase in velocity would be limited by the terminal velocity particular of that shell which is the same for any given altitude and if the shell does increase its momentum [ something I do not believe possible; Conserve maybe, but not increase] there would be an increased in both parasitic, aerodynamic drag as the thicker atmosphere is encountered and that would counter any increases so I refuse to believe that there such an increase in final velocity. This is confirmed if the reader takes the time to plug some different height values into the free fall equations found online at .http://hyperphysics.phy-astr.gsu.edu/hb ... lq.html#c1
which confirms there is no increase in velocity due to any increase in height that would effect any vertical component of the shell's momentum. Flight time and range are the same or very close as is clearly shown.
Can anyone give me logical answer other than the Rout answer "That is what was believed to be the case at the time so it must be true!"