Machine guns....

[Knarley-Bob]

Nope, not doing the 50 cal thing.

Was wondering about the conversion point of the guns in front of one's aircraft.

By my way of thinking, which is usually flawed, the aircraft with the guns on the nose, and thru the prop hub, don't really need to have a convergence 'spot' as they are so close together. On the other hand, wing mounted guns would need to be aligned as to have a convergence 'spot'. Now as I understand it, there are different ways to set that 'spot'. I will use USAAF planes as I am more familiar with those. Now correct me if I am wrong, but, weren't the guns on let's say a P-47 capable of being set up to 4 different convergent points? That would give the pilot a 'focus of fire' from say 200,250,300,350 yards at one time? Depending on how each pair of guns was set. There were also able to set them all to one point. I would imagine that the P-51 would also be capable of that, with the P-38 not so much. But in the sim, only one convergence spot is available.

I don't know how the guns are set up for other planes, I will leave that to the experts.

Liking that of a long shot gun string, the fire power of said aircraft would be enhanced. And the factor of putting bullets on target would improve, no?

I know that the people programming all this stuff are busy, I do not envy you your task. Just some food for thought

KB

[357th_KW]

 

[Jaws2002]

There were many way to setup the convergence, as VBF-12_KW  posted above, from concentrated point to shotgun pattern at certain range.

The nose mounted guns also had to be setup properly, because bullets fly in an arc, not straight line like lasers, so they were setup for the "vertical convergence". Bullets would fly upwards, over the flightpath and then drop back in the gunsight at certain range. Heavy cannons with lower muzzle velocity had quite a drop, so vertical convergence was important, even for aircraft with nose mounted weapons.

 

Edited November 5, 2021 by Jaws2002

[Knarley-Bob]

Sorry I blew up. All I have to go by is the setting from 100 to 1000 for convergence before I hit accept.

 Figuring that all were pointed at the same spot. My bad.

I do realize that if on shoots a bullet horizontally, and drops a bullet from the same height and same time, they will hit the ground at the same time.

I do have just a 'little' experience with firearms.?

KB

[Yogiflight]

26 minutes ago, Jaws2002 said:

Bullets would fly upwards, over the flightpath and then drop back in the gunsight at certain range.

Mainly correct, but the bullets of the engine guns of the Bf 109 F-K were flying parallel to the engine mount, which means 40',(2/3 of a degree, if I am not completely wrong) upwards, so more or less horizontally. For the convergence setting, the gunsight was set, so the pilot's view crossed the trajectory of the bullets in 400m (later models 500). Then the machineguns were set to convergence.

I would guess, that it was the same for the 110, with its 20mm guns being located under the radio operator's compartment. So it would have have been difficult to let them shoot upwards.

[LukeFF]

30 minutes ago, Yogiflight said:

Then the machineguns were set to convergence.

 

Most of the time, the MGs were set with parallel convergence, i.e., they did not converge at a set range. 

[Knarley-Bob]

I was under the impression that they would be set on a horizontal convergence and parallel also, windage & elevation. There is no sense having them converge one way and not the other. Of course that would make sense........

Having the inboard set at 200, the next set at 250, the next set at 300 and in the case of the p-47 the next set at350 would give one good coverage.

Now strafing one would want the convergence to be out there a ways..one would think.

KB

[Jaws2002]

1 hour ago, Yogiflight said:

Mainly correct, but the bullets of the engine guns of the Bf 109 F-K were flying parallel to the engine mount, which means 40',(2/3 of a degree, if I am not completely wrong) upwards, so more or less horizontally. For the convergence setting, the gunsight was set, so the pilot's view crossed the trajectory of the bullets in 400m (later models 500). Then the machineguns were set to convergence.

I would guess, that it was the same for the 110, with its 20mm guns being located under the radio operator's compartment. So it would have have been difficult to let them shoot upwards.

 

Yes, the motor cannon was coaxial with the engine, but the engine was pointing slightly up (two third of a degree) and that brought the bore axis up by four meters at 400m. The 30mm MK108 trajectory was coming back down in the gunsight at 400m.

 

Edited November 5, 2021 by Jaws2002

[Avimimus]

This is where having something like a 'historical preset' that overrides convergence settings for all of the guns and gives them custom individual firing angles (based on historic documents) would be pretty neat as a feature in the distant future. It'd change things a bit (especially the aircraft that had 'box' convergence). One of many possibilities to dream of.

[DD_Arthur]

7 minutes ago, Avimimus said:

This is where having something like a 'historical preset' that overrides convergence settings for all of the guns and gives them custom individual firing angles (based on historic documents) would be pretty neat as a feature in the distant future. It'd change things a bit (especially the aircraft that had 'box' convergence). One of many possibilities to dream of.

 

Now that is great idea?

[Yogiflight]

1 hour ago, LukeFF said:

 

Most of the time, the MGs were set with parallel convergence, i.e., they did not converge at a set range. 

Yes, that's right. I was only talking about vertical convergence. Horizontal convergence wouldn't have made a lot of sense.

[Knarley-Bob]

1 minute ago, Yogiflight said:

Yes, that's right. I was only talking about vertical convergence. Horizontal convergence wouldn't have made a lot of sense.

How so?

[Yogiflight]

Just now, Knarley-Bob said:

How so?

They are less than half a meter apart from each other and in front of the pilot. There is no need to get them shooting at one spot. It is completely different for guns in the wings, where you either want to concentrate on one spot, or spray over a certain distance to have a larger chance to hit. Here it is the way you explained it above with the      P 47.

[Mtnbiker1998]

43 minutes ago, Avimimus said:

This is where having something like a 'historical preset' that overrides convergence settings for all of the guns and gives them custom individual firing angles (based on historic documents) would be pretty neat as a feature in the distant future. It'd change things a bit (especially the aircraft that had 'box' convergence). One of many possibilities to dream of.

I'd rather this be the only option. I doubt many pilots outside of the highest scoring aces would have had the pull to get their aircraft setup just the way they liked, considering the amount of work that would go into boresighting guns. Especially with nations that didn't operate on a "personal aircraft" basis.

[Knarley-Bob]

5 minutes ago, Yogiflight said:

They are less than half a meter apart from each other and in front of the pilot. There is no need to get them shooting at one spot. It is completely different for guns in the wings, where you either want to concentrate on one spot, or spray over a certain distance to have a larger chance to hit. Here it is the way you explained it above with the      P 47.

Perhaps I didn't explain it quite right. The way I am looking at it, a pair of guns is each inboard gun on each wing.  they are the closest together, and converge at say 200 yards. the next set, is the two on each wing out, set at 250 yards, the next set, which is out board further is set at 300 yards, and so forth. Your spread is going to be longer, hitting the target in the back, and front, at the same time.

1 minute ago, Mtnbiker1998 said:

I'd rather this be the only option. I doubt many pilots outside of the highest scoring aces would have had the pull to get their aircraft setup just the way they liked, considering the amount of work that would go into boresighting guns. Especially with nations that didn't operate on a "personal aircraft" basis.

This is true, I'm sure each group had their way to do things, but I'm also sure that it would depend on their type of missions they usually flew.

But, if there is documentation on how it WAS done, there ya go...........

KB

[Mtnbiker1998]

4 minutes ago, Knarley-Bob said:

 

But, if there is documentation on how it WAS done, there ya go...........

 

Check the post that VBF-12 linked, its got quite a bit of good information in it.

[Yogiflight]

1 minute ago, Knarley-Bob said:

Your spread is going to be longer, hitting the target in the back, and front, at the same time.

More hit at all, if you don't know the exact distance. You have a spread between 200 and 300 (P 47 even 350) yards, no aircraft is 100 or 150 yards long. It is the shotgun principle. Spray to increase the chance of hitting.

[Knarley-Bob]

1 minute ago, Yogiflight said:

More hit at all, if you don't know the exact distance. You have a spread between 200 and 300 (P 47 even 350) yards, no aircraft is 100 or 150 yards long. It is the shotgun principle. Spray to increase the chance of hitting.

No it isn't. Say we are shooting at a target that is 200 yards. If you shoot at the bull's eye with a gun that is sighted in for 300 yards, you will still hit the target, only higher on the paper. If then you shoot at it with a gun that is sighted at 400 yards, you will hit the target a little higher yet. It all depends on the drop rate of how fast the bullet is going and how heavy. The same will hold true for the horizontal plane except one doesn't figure in drop. 

[BlitzPig_EL]

What I would like is to be able to set both the horizontal, as well as the vertical convergence.   Having the horizontal set to say 250 or 300 and the vertical set to 500 would make for some interesting deflection shots.

[Knarley-Bob]

That's what I thought they could do......

Looks like am mistaken.

31 minutes ago, Mtnbiker1998 said:

I'd rather this be the only option. I doubt many pilots outside of the highest scoring aces would have had the pull to get their aircraft setup just the way they liked, considering the amount of work that would go into boresighting guns. Especially with nations that didn't operate on a "personal aircraft" basis.

It would be interesting to see how they 'bore sighted' these guns, seeing as how one needs to be able to see through the bore to do that.

[Rjel]

1 hour ago, Knarley-Bob said:

That's what I thought they could do......

Looks like am mistaken.

It would be interesting to see how they 'bore sighted' these guns, seeing as how one needs to be able to see through the bore to do that.

I would think a bore mirror of one sort or another.

[Raven109]

Slightly offtopic...

 

 

 

 

 

 

 

[II/JG17_HerrMurf]

Boresighting only gets you in the right zip code anyway. Actual sighting in requires putting rounds on paper down range.

[Knarley-Bob]

2 hours ago, Rjel said:

I would think a bore mirror of one sort or another.

Those will let one look at the bore. Inspect the the rifleings and such. Kinda like a bore scope.

[Yogiflight]

12 hours ago, Knarley-Bob said:

No it isn't. Say we are shooting at a target that is 200 yards. If you shoot at the bull's eye with a gun that is sighted in for 300 yards, you will still hit the target, only higher on the paper. If then you shoot at it with a gun that is sighted at 400 yards, you will hit the target a little higher yet. It all depends on the drop rate of how fast the bullet is going and how heavy. The same will hold true for the horizontal plane except one doesn't figure in drop. 

Thinking back to my time in German army, I have to admit, you are right, at least if you are shooting at the fuselage. Our G3 gun had a drop of 8cm per 100m inside the fighting distance of 400m, so it definitely works for a fuselage.

If you are shooting at a fighter wing from the dead six though, you might end with the shotgun principle, where your three or four pairs of guns give you hits, where one pair might see the bullets pass over or under the gun, especially if not shot at convergence distance.

[Knarley-Bob]

So, I guess the next questions would be what is the best way to use what we have here on the sim? How does it work ? What does it do? And for what planes?

Time to sit back and learn a little...........

KB

[69TD_Hajo_Garlic]

30 minutes ago, Knarley-Bob said:

So, I guess the next questions would be what is the best way to use what we have here on the sim? How does it work ? What does it do? And for what planes?

Time to sit back and learn a little...........

KB

I use 600m on planes with centerline weapons, this helps with deflection shooting and you only have to shoot a little low up close. This also helps with the mk108 and m4 cannons imo. The la5 and mig3 I like a 400m convergence for the nose cannons. Planes with wing guns I prefer 300m. I wish I could just set and forget once for each plane or just use the historical setting. 

[II/JG17_HerrMurf]

If I'm going to dedicate to ground attack I'll push the convergence out to 600 to get that extra split second of setting up the attack. For everything else I've found 400 seems to be the sweet spot for me, nose or wing mounted.

[BlitzPig_EL]

I use 500 for nose mounted guns, and 300 for wing guns.

[Alexmarine]

My personal preferences:

 

British planes 230 or 270m (later one especially if I know I'll strafe ground targets)

 

US planes 320m for all except 420/450m for the P-38 and 400m for the P-39

 

USSR planes: 400m for all except 300m for Il-2 and I-16 (sometimes 250m for the ishak)

 

Axis planes: usually 500m except 300m for the Stuka and the Henschel and 250m for the E-7 and the 202

 

 

[Rjel]

5 hours ago, II/JG17_HerrMurf said:

If I'm going to dedicate to ground attack I'll push the convergence out to 600 to get that extra split second of setting up the attack. For everything else I've found 400 seems to be the sweet spot for me, nose or wing mounted.

I do similar for ground attack but IRL I doubt that would be a doable option for a fighter group when getting ready for a mission. Imagine a late war setting where most P-51 groups were fielding double the size of a normal squadron, having to adjust the settings on hundreds of .50 caliber Brownings. 

Edited November 6, 2021 by Rjel
spelling

[II/JG17_HerrMurf]

3 hours ago, Rjel said:

I do similar for ground attack but IRL I doubt that would be a doable option for a fighter group when getting ready for a mission. Imagine a late war setting where most P-51 groups were fielding double the size of a normal squadron, having to adjust the settings on hundreds of .50 caliber Brownings. 

 

There was a similar discussion way back in EA. It was stated, changing convergence could be done at the group level if the long term mission was going to be dedicated to ground attack but no lower command could authorize it. I'm not sure if there was any documentation submitted to support the statement. Certainly no individual pilot could just decide to change his convergence on his own - outside of maybe some of the German posterboy experten.

[AEthelraedUnraed]

It seems I shoot from shorter ranges than most here. Between 200 and 250m in all aircraft, except when I'm doing ground attack, in which case I use 500m. I usually find 200m to be a bit too much, but decreasing it even further makes it harder to hit targets at longer ranges.

[Fritz_X]

7 hours ago, AEthelraedUnraed said:

It seems I shoot from shorter ranges than most here. Between 200 and 250m in all aircraft, except when I'm doing ground attack, in which case I use 500m. I usually find 200m to be a bit too much, but decreasing it even further makes it harder to hit targets at longer ranges.

 

I'm right with you.

 

After flying axis exclusively for a while, I recently returned to flying my favorite aircraft, the Spitfire. Before taking the break, I always set my convergence to 280 m, but now I toned it down to 240 m. And I have to say, that hitting (airborne) targets has become easier this way for me. I also tested this setting on the Tempest and the P-51, which gave me better results than before on both aircraft as well.

 

I will play around with other settings close to this value on my next sorties, but for now 240 m is my prefered setting for (far out) wing mounted guns.

 

On planes that use centerline mounted guns only I use a value 340 m, on planes with additional guns mounted in the wing roots (like the FW-190 family) I prefer a convergence of 280 m.

 

In the end it all comes down to personal taste and playstyle.

[Yogiflight]

I always use the historically correct convergence, where I know it, so usually 400m.

Those, who use shorter convergence settings should remember, if it is modelled correctly, the 400m convergence for the 109 for example means the bullets cross the sight line at 125m for the first time and the fly over the sight line until they cross it the second time at 400m. So for deflection shooting this setting should be much better than a shorter convergence, because of the bullets being over the sight line at the important distances for turn fighting, you don't need as much lead as with a shorter convergence setting.

[Yogiflight]

It might be an interesting addition in game to have the historically correct convergence settings mentioned in the aircrafts specifications. It might be an interesting orientation aid for players, who don't know how to set their convergence.

[Knarley-Bob]

With the planes who have the guns close together, on the nose I usually set the convergence to 1000. They are close enough the way it is. Now the Spitfire has them spread quite far apart, there is where one must consider 'doing the math' so to say. In closer for areal combat, and out further for strafing. What's nice about the the sim, is no crew chief to get mad at'cha. Still don't know how they have it set for the sim here.

KB

Edited November 7, 2021 by Knarley-Bob

[RyanR]

This thread is timely. Does anyone know a source for historical settings for the P-51 and P-47? I think default is 600m.... but I seem to recall 300 yards being more correct. It would be nice to have a "set and forget" ability for a given plane.

 

It's really just these two aircraft that even make me think about convergence. There's no point in having the convergence out beyond where kinetic energy is all used up.

 

-Ryan

 

 

[LukeFF]

1 hour ago, RyanR said:

This thread is timely. Does anyone know a source for historical settings for the P-51 and P-47? I think default is 600m.... but I seem to recall 300 yards being more correct. It would be nice to have a "set and forget" ability for a given plane.

 

For the P-51, 250 and 300 yards are mentioned most frequently in the official manuals. For the P-47, it's 250 and 350 yards. 

[Rjel]

In the book, Pursue and Destroy by Leonard "Kit" Carson, there is a mention that the wing guns on a P-51 could be adjusted from 150 yards to 400 yards. I haven't been able to find that in this manual yet but it makes sense. There is limited room within the gun bay to move a trio of heavy machine guns around obviously. Below are some diagrams showing the .50 cal setup in a P-51D-5. I wonder if this is the same dispersion used in the Mustang in our sim?