Centerline Guns configurations

[Tony Williams]

Actually the Germans did catch on to the "load a few tracers at the end of the belt" approach.

I have read that wartime experience among USAAF fighter units in Europe revealed that squadrons which used tracers suffered more losses and scored fewer kills than those which didn't.

OTOH, tracers were popular with bomber gunners as the sight of the tracers flying towards them might make the attacking fighters flinch. The US even developed a special .50 cal tracer round, the ""Headlight", which was designed to be extra-visible from the front in order to emphasise this effect.

 

[renrich]

Another point to consider on wing mounted versus nose-fuselage mounted guns. A stoppage in a wing mounted gun, especially a cannon can cause the AC to yaw badly. A stoppage in a nose monted weapon will not have much effect.

 

[HoHun]

Hi Renrich,

>Another point to consider on wing mounted versus nose-fuselage mounted guns. A stoppage in a wing mounted gun, especially a cannon can cause the AC to yaw badly. A stoppage in a nose monted weapon will not have much effect.

Good point! At least the P-51 manual warns against firing anything but short bursts if one wing gun is jammed because its impossible to compensate accurately for the yaw by the use of rudder. I think Freeman's "Combat Profile: Mustang" actually features a combat report from a fighter pilot who had an asymmatric jam (of several guns, if I remember correctly).

Regards,

Henning (HoHun)

 

[Burmese Bandit]

Another point regarding centerline gun mounting on aircraft performance (and I am surprised that the extremely knowledgeable people on this forum have not commented on this before) is that all other things being equal, not mounting guns in the wings makes an aircraft more responsive to rolling manuevers and holds open the possibility of designing the wing to be lighter, therefore increasing the manueverbility of said plane.

Furthermore, why has no one pointed out the fact that very powerful wing-mounted guns firing heavy bullets and shells can flex the wings when firing, leading to ammo dispersion problems and heavy plane vibrations?

 

[Burmese Bandit]

Er, just noticed that drgndog has pointed out that second point in his post, though only in passing, and he didn't mention the handling problems caused by flexing wings.

 

[looney]

I've read also that the guns of a spitfire had different convergence for the different guns. Although I understand it would be good for the pilot to see his round hit, it also makes his guns less effective.
Also the spitfire couldn't get the convergence as close as the pilots would like. I believe the minimum distance for the the inner guns was 180m. While dogfighting took place at much closer ranger (80-150m, some even closer, check Hans-Joachim Marseille and ofcourse Erich Hartmann as close as 20m ), even British aces hated that long convergence range of the spit (can't find my source again). However the factory standard was a whopping 350m (some Osprey book I read)

Therefore I think that the 20mm + 2x 7.9mm armament of a BF109 is much more deadly than the 8 0.30 of a British early war fighter. Even late war the above mentioned armament can keep his own against wingmounted 20mm's

 

[drgondog]

I've read also that the guns of a spitfire had different convergence for the different guns. Although I understand it would be good for the pilot to see his round hit, it also makes his guns less effective.
Also the spitfire couldn't get the convergence as close as the pilots would like. I believe the minimum distance for the the inner guns was 180m. While dogfighting took place at much closer ranger (80-150m, some even closer, check Hans-Joachim Marseille and ofcourse Erich Hartmann as close as 20m ), even British aces hated that long convergence range of the spit (can't find my source again). However the factory standard was a whopping 350m (some Osprey book I read)

Therefore I think that the 20mm + 2x 7.9mm armament of a BF109 is much more deadly than the 8 0.30 of a British early war fighter. Even late war the above mentioned armament can keep his own against wingmounted 20mm's

I just uncovered an article about S/Sg Charlest Klein, line chief of armament for 357FS/355FG who designed and built a periscope bore sight to place in the Browning M2/M3 breech in Spring 44. It was used to boresight the early P-51B's, dramaticaly improved boresight cycle times and accuracy. The 'single shot' pattern was established as a two foot wide/tall hexagon at 200 yards. IIRC there were no exceptions to the approved pattern or boresight distance in the 355th/2SF Mustangs based on some pilot's desire to get a shotgun pattern, etc. Basically "if you don't like it, transfer!"

Although it would work for any range the 355th set theirs at 200 yard convergence. NAA modified the boresight tool to put a riflescope cross hair (Klein used a fine wire crosshair with no lens) and telescopic lens and issued them with all the new P-51D's.

He received a bronze star for that plus improving the buffer spring/plate on the .50 cal which greatly reduced the stoppages in the .50's..

 

[looney]

200y roughly 190m. Sounds about right, only aces set them closer usually. They wanted a harder punch. As I read the brits reduced the range during BOB from 350 to 180 on the inner guns (the rest where set at the same angle, thus getting 3 different ranges).

Fact remains that centerline guns where easier to aim and have overall more hitting power, not?

 

[Sydhuey]

Reports I have read from US pilots who had flown various types talked about how the P-38 with 4 x .50 and 1 x 20mm concentrated in the nose was one of the most liked setups as all in centre line and better for snap shooting, P-47 with 8x.50 best for ground straffing, good spread and high volume of fire, most pilots considered 6 x .50 min setup for wing guns , one reason why the P-40 N went from 4 x .50 back up to six after the first models hit the field was complaints from pilots who had 6 x .50 in E,F,L,M model didn't like dropping to 4 in the N.
Also on the problem with G loading of ammo feed of wing guns the B/C model Mustang had a lot of jam problems with there 4 x .50's the D model had different feed shutes and the guns at a differant angle to aleviate the G loading jam problems

 

[vanir]

The Luftwaffe was fairly evenly split over how many pilots preferred wing or centreline guns, generally you can pack in more guns into the wings and some go for that. I think fighter planes are a case of build it and they will come. So long as it's got guns and they work, somebody will get some deadly effect from them.