05.01.2011, 02:05
If, for example, your 100 mils ring matches a 100 mils target (irrespectively of its distance) - radius or diameter - then your reticles are of the correct size. They were actually designed for eyeballing application, so this should be the ultimate test.
This is one of the manuals:
http://www.mediafire.com/?yzjwn3mjdne
which explicitly describes when a radius was used (target speed estimation) and when a diameter was used (target distance).
Concerning the navy reticle, if the large ring was 200 mils in diameter, it could have been seen as about 90-100 mm circle from a typical viewing distance of 450-500 mm. The Mk. 8 gunsight had a glass about 95 mm wide (3-3/4" x 5-1/8" x 1/4"), such large reticle would never be visible in its entirety. To see the entire reticle, 300 mils wide end to end, one needs to get as close as 280 mm to the gunsight. Also, if the "100 MILS" writing referred to the radius, it would be more logical to place it on one side of the center line rather than in the middle and above the 200 mil circle. Still, the sight could have been designed that way.
Do you actually have any explicit reference to the ladder marks being spaced 10 mils, or ring radii being 50/100 mils?
It would be nice to get hold of some of them, just to avoid any confusion in the future.
This is one of the manuals:
http://www.mediafire.com/?yzjwn3mjdne
which explicitly describes when a radius was used (target speed estimation) and when a diameter was used (target distance).
Concerning the navy reticle, if the large ring was 200 mils in diameter, it could have been seen as about 90-100 mm circle from a typical viewing distance of 450-500 mm. The Mk. 8 gunsight had a glass about 95 mm wide (3-3/4" x 5-1/8" x 1/4"), such large reticle would never be visible in its entirety. To see the entire reticle, 300 mils wide end to end, one needs to get as close as 280 mm to the gunsight. Also, if the "100 MILS" writing referred to the radius, it would be more logical to place it on one side of the center line rather than in the middle and above the 200 mil circle. Still, the sight could have been designed that way.
Do you actually have any explicit reference to the ladder marks being spaced 10 mils, or ring radii being 50/100 mils?
It would be nice to get hold of some of them, just to avoid any confusion in the future.