While working on a 6000 yard ship attack gunsight for the B-25H, I've come up against a gunsight quandary. So far in testing I've hit the CV at 6000, 5500, 5000, 4000 and 3000 using the ship markers in the gunsight. From wave top level.
To use this gunsight I have to move my pilots head up until the gunsight center is just below the top edge of the very long glass reflector plate in the B-25H cockpit. In real life it was that long to allow the dial to angle it to a max range of about 5500 yards. There is a tiny trick to getting 6000. With the gunsight center and range markers for 2000 and shorter at the top of the glass plate. Attacking ground targets like tanks with the 75mm becomes dicey. ON the other hand the 5.5k marker at the bottom of the gunsight plate makes a perfect glide bomb release point diving in from 1000ft and relasing the bomb at about 400-600. Slams into the side of tanks.
I tested moving the gunsights up and down for jabo and rockets in other planes. With the A20 lowering the main ring just to the hood makes the aimpoint just at the bottom of the inner small ring diving in from 1000ft releasing about 800. But, it needs to be rehomed to center for air to air gunnery. I tested killing a T-34 with an FW190 F8. I raised up the Revi so their was space between the bottom of the ring and the forward deck. Went out with a 250kg bomb and rockets. Starting from 1500ft diving to 1000ft on wep to bring my speed to 300. Then dove to the T-34 releasing the bomb about 600-800. Tank goes boom. Same run up with rockets. Dove in using the first Revi tick mark down from center, single rocket shot. 8 out of 12 hits. Tried this with the Typhoon. Raised the gunsight. The rocket aid is about 25mil down from center. 3 kills on the T-34, rest misses by feet because of not allowing for the distance out from the gunsight center to the rockets under the wings.
If I have to fight another plane in my jabo or those two bombers, I would prefer the ring centered.
So the wish.
I wish for attackers and medium bombers with a gunsight to have two forward saved views on a toggle. This will allow setting the gunsight in two positions.
Eventually the K14 had a tilting reflector plate. Obviously the N3 in the B-25H has one. Some A20 were mounted with N3, all models with 20mm were mounted with N3 by Douglass. Later British Barr&Stroud gunsights had either a tilting head for rockets and bombs MKIIL. Or an internal adjustment to refocus the ring and dot Type I MkIII. The Revi had a tilting base plate to assist with jabo. The PBP 1B had windage, elevation, and azimuth dials in bombers.
Sadly it was not until Korea and Viet Nam that the later Mk20 development of the Mk8 had adjustment dials.
