Author Topic: What is a Gunsight to You?  (Read 2567 times)

Offline bustr

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Re: What is a Gunsight to You?
« Reply #30 on: August 23, 2013, 07:15:44 PM »
The diagram is from the AAF, Manual for Fighter Gun Harmonization, 200-1, 30 January 1945.

Harmonization was accomplished with the understanding that as your rounds went out along their ballistic arc. They also described an average 4Mil diameter dispersion ring at any distance to 2000ft(666yds). Or the AAF tested AtoA max effective distance for ww2 air combat.

The gunsight view line or center line was aligned to the horizontal convergence point in a Hi, Mid or Low orientation after the IP point, convergence point, and dispersion pattern was achieved at the targeted distance. Essentially by design never having the bullet stream pass above the sight line other than by dispersion, as we see accurately depicted in the game.

When you look at the diagram you can see why the most common shooting mistake for 47 pilots in the game is shooting too low before the harmonization point. And needing experienced skill to hold the stream steady for the kill at the convergence point or past while closing into a target. The guns are almost 5ft below the gunsight center line. At distance small variations in vertical AoA translate into large motions and misses. But, then the rendering of those dispersion clouds was to show the advantages of the dispersion as a shotgun making random hits very likely inside of that 4Mil circle at distance.

The same manual from which this P47 diagram comes from has a second one for the P47 showing convergence set with all guns crossing at the same point along with diagrams for the P38, P39, P40, P51B and P51D. It has data tables for the common rounds of the period 50cal to 75mm relative to drop at range, time to target, air speed, alt and air density. This was so the armorer could manually calculate bore sighting targets with convergence and gunsight line of sight.

Hitech's convergence application standardizes this process. One gun or pair of guns is tied to the gunsight line of sight. Either the LoS is fixed and as you pull the convergence in or out, the IP is at the LoS for that range. Or the LoS changes slightly like with the MK108 in the K4 due to it's radical ballistics. Offline, fly auto level in the K4 at 307ias, 1000ft. Have the cannon set to 150. Pull up the offline target at 437yd(400m). The center of your gunsight pipper will be about 11ft below the red horizontal line on the target. Each ring is 10ft wide. And so to your 30Mil dispersion cloud will be generally around that same point if you tap several rounds and not hold down on the trigger.

So all of you engine mounted nose cannon guys. If you are into realism, pull your nose cannon into 150, and learn to shoot "ww2 style". Changes the game realism factor a bit.

Hmmm, wonder why Hitech doesn't lock all internal engine nose cannon(Daimler-Benz, Junkers Jumo) to 150 at least. They were not adjustable in real life due to the tube inserted through the engine block that the cannon was then inserted into. Only the hood MG, gondola, and wing root cannon. Yak gunsights were pre adjusted to 200m(218yd) with a mark on the back of the prop to allow the pilot to check for that convergence alignment. Ergo, the LoS would be slightly down to a point 200m passing through the expected ballistic drop point of the 20mm round at 200m from engine level. Inches below the red horizontal line on the offline target at 218yds.

From the Bf109-G6/U4/Wa single MK108 handbook.
Gunsight line at 400m(437yds) -11ft
MK108 IP at 400m(437yds) -11ft

In Hitech we trust, pass the ammo.......

bustr - POTW 1st Wing


This is like the old joke that voters are harsher to their beer brewer if he has an outage, than their politicians after raising their taxes. Death and taxes are certain but, fun and sex is only now.

Offline SIK1

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Re: What is a Gunsight to You?
« Reply #31 on: August 23, 2013, 07:24:07 PM »
I too just use the dot o' death The others seem overly cluttered for me. I have my head position so the dot is just at the top of the sight reticle.
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Offline icepac

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Re: What is a Gunsight to You?
« Reply #32 on: August 24, 2013, 11:54:53 AM »
HTC allows convergence settings for centerline guns for reason of "vertical convergence".

Remember, we're talking about 2 axis here.

Offline BaldEagl

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Re: What is a Gunsight to You?
« Reply #33 on: August 24, 2013, 12:55:11 PM »
2. - Point here, pull trigger, go boom
I edit a lot of my posts.  Get used to it.

Offline Karnak

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Re: What is a Gunsight to You?
« Reply #34 on: August 24, 2013, 01:34:27 PM »
4, 2 and 5, in that order.
Petals floating by,
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             As she remembers me-

Offline bustr

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Re: What is a Gunsight to You?
« Reply #35 on: August 24, 2013, 02:20:59 PM »
ice,

The PBP LoS is fixed slightly down. The green line for the ShVAK slides along it to adjust it's vertical convergence point relative to that junction.

Why do you think over the years I've constantly bored you guys to death telling you to fly offline at the IAS speed that levels the engine line to the red horizontal line of the target? Then shoot at every 50 yards starting at 100 to 650. Then keep record of the relationship of the reticle center to the target horizontal center line and then the relationship of your IP point to both that line and your reticle center point. In effect your armorer did on paper that when he bore sighted your guns, then adjusted your gunsight to that pattern.

I gave up supplying Boresight.bmp with my Historic packages with it's Mil rule crosshairs(2.5, 5, 10) to perform exactly that testing. It's inspired by a gauge used to center AAF gunsights after the guns were adjusted to the harmonization target created from the data in the AAF Manual 200-1. I realized too late I should have provided a Mil at distance plug in calculator to reduce the results to feet at hundreds of yards at the onset of supplying the tool.

I may have caused more confusion than helped since, 4Mil @ 200yds is smaller than 4Mil @ 600yds.
bustr - POTW 1st Wing


This is like the old joke that voters are harsher to their beer brewer if he has an outage, than their politicians after raising their taxes. Death and taxes are certain but, fun and sex is only now.

Offline Ruah

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Re: What is a Gunsight to You?
« Reply #36 on: September 27, 2013, 10:23:40 AM »
4.

Basically use the historically or near historically correct gunsights on all the planes (sans bombers)

most of the time I don't need the sight, but it helps in super high speed/high deflection stuff.

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Offline save

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Re: What is a Gunsight to You?
« Reply #37 on: September 28, 2013, 07:19:36 AM »
4
My ammo last for 6 Lancasters, or one Yak3.
"And the Yak 3 ,aka the "flying Yamato"..."
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Offline madrid311

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Re: What is a Gunsight to You?
« Reply #38 on: October 03, 2013, 02:30:05 AM »
where do I get a gunsight Package download? 
Quote from: hitech on Yesterday at 11:15:04 AM              
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Offline Citabria

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Re: What is a Gunsight to You?
« Reply #39 on: October 03, 2013, 03:48:47 AM »
"you don't need all that #!#! just stick a piece of gum on the window and your good to go" -Gabby Gabreski

I subscribe to the gabby philosophy of less is more.

wimple dot or a dot with a ring around it is plentry.
Fester was my in game name until September 2013

Offline Tilt

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Re: What is a Gunsight to You?
« Reply #40 on: October 03, 2013, 09:19:28 AM »
2
Ludere Vincere

Offline bustr

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Re: What is a Gunsight to You?
« Reply #41 on: October 03, 2013, 06:44:40 PM »
Gabby Gabreski had the 56th use British MkII because they were superior to AAF N-3 for lead shooting because of the very large ring. Nearly all AAF fighters reaching depots in England had their N-3 thrown in piles and replaced with MkII. P47 pilots long after the Mk8 was standard equipment up to the K14 becoming the default in bubble canopy deliveries and field mods. Stayed with their MkII. All of the 56th cockpit photos from WW2 I find, they have a MkII under the hood. I find the same in P51 and P40 photos that passed through depots in England.

Some of the source for the Gabreski chewing gum legend.

World War II came to an end and Gabreski resumed his flying career, but now as a USAF test pilot. Eventually he found employment with The Douglas Aircraft Corporation, but this was only temporary, as a new war had come on the scene. Korea!  Gabby returned to serve the USAF, this time as ‘Lieutenant-Colonel Gabreski’ – commanding officer of an F-86 Sabre squadron. According to legend, Gabreski was not familiar with the more modern gunsight and chose instead to rely on a piece of chewing gum stuck on the windscreen. In spite of this minor obstacle, the World War II veteran scored no less than six and a half MiG-15 kills during the Korean War. This meant that Gabby had become one of a handful of pilots to achieve ‘ace’ status in both World War II and in Korea.

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Seems Gabreski had problems with the early active lead computing gunsights. More of the source for the chewing gum legend.

The A-1C(M) gunsight: a case study of technological innovation in the United States Air Force.

The A-1C(M) lead-computing sight was the first fighter gunsight to employ radar ranging. It was widely used in Korea where it received a mixed reception by the F-86 pilots who depended upon it. Many of the younger, less experienced pilots found it a godsend, while the veterans, particularly some aces of World War II, considered it unreliable and much too complicated--particularly its radar. Nevertheless, the introduction of the A-1C gunsight was an important milestone in the development of sophisticated fire control equipment for air-to-air combat.

 The story of the A-1C provides evidence of the importance of the heterogeneous engineer in developing new technology and the impact of "innovative departure" on the users of a new weapons system. It also provides insight into the non-technical problems that often arise when a new weapons system is introduced.

Jump to Gabreski's challenge of the A-4. A-4 is the A-1C with all of the bugs worked out and enabled higher Saber kills than Mig in Korea. And the chewing gum legend

Col. Francis S. "Gabby" Gabreski, considered by many to be a "fighter pilot's pilot," was the senior member of the team. (48) He was flamboyant, heroic, and had been the leading U.S. fighter ace in the European Theatre during World War II. In June 1951, Gabreski, then in command of the 56th Fighter Interceptor Wing, was posted to Korea. He flew 123 missions in the F-86E and was credited with an additional 6 1/2 MiGs, making him one of only six U.S. Air Force pilots to have achieved the distinction of becoming an ace in both conflicts.

 But Gabreski has been chastised for ignoring his wingmen. He flew the fastest aircraft available and would not respond when wingmen could not keep up. (49) He was also criticized for a lack of discipline among his off-duty pilots, and for allegedly encouraging exaggerated kill claims.

Gabreski did not like the A-1C sight. He often claimed that he "could do better with a piece of chewing gum in the windshield," which he may have used in place of the A-1C on more than one occasion. (50) He came to Eglin to prove that the K-14 would show much better results. (51) During the flying portion of the project, Gabreski, using the K-14, was paired against Col. James K. Johnson, using the A-4. Johnson, called "Rabbit" because of his quickness as a pilot, was one of the test pilots chosen to replace two of the original test team selectees who had not arrived in time for the fly off. He had yet to fly in Korea where he would become a double ace, but he was an experienced combat veteran of World War II.

 Before taking off, Johnson asked Gabreski where he wanted the pipper to be. He had to badger the unresponsive ace for an answer. Gabreski finally said, "Just put the pipper on the cockpit!" (52) Johnson was an extremely smooth pilot who made good use of the A-4. When the gun camera films came back, almost every frame showed Johnson's pipper right on Gabreski's cockpit.

 When Gabreski's turn came to be the attacker he told Johnson to "hold it" so that he could bore sight the camera that was rigged through the K-14. As soon as he was lined up on Johnson's tail he triggered the gun camera and radioed "fights on." When Gabreski's film was developed Johnson's tail pipe was in the center of the first few frames, after that, all you saw was sky, because Gabreski was not able to get in another shot at Johnson once he started to maneuver defensively. (53)
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One of the issues with K14 in jets was the higher E load reached faster that locked up the gyros or moved the pipper out of sight do to not having a maximum deflection range limiter. Same problem happened in ww2 with the K14, you either dmaged the gyros or got the 6-star back functioning when you let up on E load. The next generation A-1 to A-4of radar enhanced guns sights for the F86 in Korea addressed that issue. Robert Johnson probably knew this and made a fool out of Gabreski to prove that point.

Boots Blesse said this about the Korean War family derivatives of the K14 first used in the F86. And where Gabreski may have been forced to use chewing gum.

"The earlier gunsights had a pipper in them and if you didn’t have this range limiter to set, the pipper would go off the screen when you turned sharply, and it wouldn’t display, because you needed more lead than it could give you. Until you backed off on the "G’s," the pipper wouldn't come back. Well you can’t do that in a fight. So that wasn’t very useful to us."

Doing all of the research on ww2 gunsight technology so I could create the historic reticles. Returned mountains of modern day fallacies accepted as history. And in our game we compound them x1000 many times because we take them for face value and distribute and defend them as gospel.



bustr - POTW 1st Wing


This is like the old joke that voters are harsher to their beer brewer if he has an outage, than their politicians after raising their taxes. Death and taxes are certain but, fun and sex is only now.

Offline Tank-Ace

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Re: What is a Gunsight to You?
« Reply #42 on: October 03, 2013, 07:27:28 PM »
2 and 4
You started this thread and it was obviously about your want and desire in spite of your use of 'we' and Google.

"Once more unto the breach"