Hawker Hurricane Mk. IIB vs. Grumman F4F-4 Wildcat

slaterat · 03-02-2008, 10:37 PM

The effective range of the 303s would be much shorter than the .50s. However using a box convergence, in stead of a point, at 150 yards, would be deadly against unarmoured Japanese aircraft. I would think that the dixon/dewild ammo would be devasting to the fuel tanks. 12 303s puts out more lead than a minigun.

The IIb was considered the best air to air fighter of all the Hurricane mks. The IIc with 4 x20mm lost some handling and speed because of the extra weight and drag of the cannons. Howevere in the North Afrika desert and in Burma , many IIc units deleted 2 of the 20 mm cannons in the interest of better performance. These would certainly be very close or equal to IIb s with the advantage of cannons.

Slaterat

kool kitty89 · 03-03-2008, 02:00 AM

In any other situation I'd opt for .50's or maybe cannon, but aganst most Japanese a/c a high volume of (nominaly inferior) .303 (or other RCMG round) could be more effective.

Plus the Brits didn't seem to shift to .50 cal guns (except in lend-lease and other US built a/c), they either soldiered on with .303's or were given 20 mm Hispano cannons often along with some .303's. Though some late model Spitfires did use 2x .50's in place of 4x .303's, there aren't alot of other examples.

Elvis · 03-03-2008, 05:47 AM

KK89 makes a good point that the English seemed to simply skip the "50 cal step" and went straight from .303 to 20mm. However, the change seemed to take most of the war.
Effective range of the .50, vs. the .30 is another consideration.
Anyone who's ever seen the Discovery channel show "Firepower" has probably seen the episode where he tests the semi-auto version of the BMG.
He was splitting concrete blocks with a single shot at 600 yds.
You'd have to point your gun at Mars and use an unusually high powered load to hope to even make it out to 600 yds. with a .30 (either "M1" or ".303")...and then there's the consideration of accuracy and effectiveness at that range, as well.

Wasn't the POA on most of the .50 cal equipped Mustangs (used as an example here) around 300-400 yds.?

Elvis

Elvis · 03-03-2008, 05:57 AM

Quote:

Originally Posted by Kool Kitty89

Plus higher muzzle velocity of the .30-06 (note aircraft versions had a higher muzzle velocity: ~870 m/s compared to ~840-850 m/s for ground units) gave the round flatter trajectory resulting in better accuracy and longer effective range

Quote:

Originally Posted by Elvis

kool kitty89,

NUTS, I forgot to include bullet drop in those figures.
When I get home, I'll fish that catalogue out again and post the drops.
How far out would you like them?
I think most factory listings go out to 400 yds.

Elvis

Kool Kitty89,

Forgive me for taking so long to get back to you on this...apparently I'm now old and quite forgetful.

I'm not at home, but I found the trajectory and velocity stats on-line.
This is from the Remington website.

Remington.com - Products - Ammunition - Ballistics

You'll notice that the MV for the .30-06 (aka .30M1) is little higher than what I quoted.
'06 rounds are loaded a little hotter these days.
The round is SAAMI rated at around 63K CUP (IIRC) and most are just loaded closer to that rating today.
I believe the WWII vintage rounds were loaded closer to 50-55K CUP, thus the slightly lower MV.
The MV for the .303 British is the only one I've ever seen listed for it.

Elvis

renrich · 03-03-2008, 12:57 PM

The Spitfire IX with the E wing used two 50s instead of the 303s. The A6M went to cowl mounted 50s in place of the 7.7s. The late model A6Ms also had armor and ss tanks. The Germans went to cowl mounted 50s in both the FW and BF 109s. The US went to all 50s on the P40s. The rationale for the 8-303s in the BOB British fighters was that it would take 266 hits from the 303 to be lethal against a bomber. With a closing speed of 180 mph and a thousand rounds per minute rate of fire per gun and only two seconds of firing time one needed eight 303s to theoretically get the job done. That formula was out the window in a head on pass. I am sure that if 50s had been available and the RAF had used them the LW would have been sorry. I have had a lot of experience with the 3006, 308 and various calibers like that hunting and some experience on the range with the M60(30

and the M2 50 cal BMG. I will go with 6- 50s all day against any WW2 AC.

kool kitty89 · 03-03-2008, 02:29 PM

But inless you have cowl/nose mounted guns convergence zone is a major factor too though .50's could be practically set farther out than .303's.

And RCMG's aside I'd thke the F4F-3's (and FM-1/2) armament over the F4F-4's in almost any situation. (particularly aganst the japanese) Fewer guns but slightly more total ammo and much longer firing time, plus the 2 added guns in the F4F-4 were placed farther out so were less acurate. They also offered less weight.

There was a reason the FM-2 went back to 4x .50's...

renrich · 03-03-2008, 02:53 PM

KK, agree wholeheartedly. The F4F4 was not big enough or with enough power to carry all the additional weight of the 2 extra guns. 4- 50s with 400 rounds was a better weapons load than 6-50s with 240 rounds. The only reason the 6 gun model was adopted was because of British insistence. Maybe the Brits had a fetish for lots of guns? Some sort of a phallic thing?

kool kitty89 · 03-03-2008, 04:13 PM

One other odd thing I remember is that when the Brits were evaluating there Buffalo I's in 1941 one of there coments was there were "too few guns" but 4x .50's are at least as effective as 12x .303 and better in most other characteristics, with better range, trajectory, penetration, and higher % of chemical load for incendary bullets. (albeit 2x synchronised and slower firing, though more acurate without convergence)

And in service Buffaloes often had 2x (and some times all 4!) .50 cal's replaced with .303 guns, to lighten the aircraft (along with liting fuel load), but the gain in performance (~100 ft/min climb and ~3 mph top speed) was not nearly worth the loss in firepower. (or range)

kool kitty89 · 03-04-2008, 02:57 PM

It also turns out (according to pilot accounts) that by the time the Buffaloes got to commonwealth forces the 4x .50's had been reinstalled.

renrich · 03-04-2008, 03:23 PM

KK, I got the formula the RAF supposedly used to decide for the 8-303s from an article about the Spitfire in the "Air and Space, Smithsonian" magazine. The formula was that 266 hits by 303s was needed to bring down a bomber, therefore at a closure speed of 180 mph, the fighter would have two seconds to make the kill if the guns were firing at 1000 rounds per minute and you had eight guns. If you do the math, eight guns are going to be putting out 133.3 rounds per second so 2 seconds will give the 266 figure. That is about the most optimistic scenario I have ever heard of. In two seconds every bullet is going to hit the target? BS If their theory about 266 303s is needed to kill a bomber is correct, I wonder that they ever had a kill. A head on pass would give even less firing time. They needed 50 cals in those Spits and Hurris. This article stated that originally the Spitfire wing was to be pure ellipsoid. When the need for 8- guns was realised, it was not a problem for the Hurricane but the Spitfire wing had to be redesigned to the shape we know now to accomodate the eight guns. They would have had an easier time with 4 50 cals.

claidemore · 03-04-2008, 08:56 PM

I believe the 8 x .303 Brownings would fire 160 rds per second (20 rds a second or 1150/1200 rds/min per gun) giving a Hurricane a firing time of 17.5 seconds, five/six - 3 seconds bursts. A 12 gun Hurricane IIb would fire 240 rds/second.

4 x .50 at 750-850 rpm would give 50-56 rds per second.

Also, I'd like to point out, that the pilots flying these planes were aware of the convergence problem, and at extremely short ranges, they were known to bring to bear the guns of one wing only, to make sure the enemy plane didn't fly harmlessless throught the 'hole'.

renrich · 03-05-2008, 09:40 AM

I hope you don't think I am saying that the 8 guns have only a 2 second firing time. The two second firing time is based on a closure speed of 180 mph(which does not sound realistic) I suppose the two second window is the length of time the fighter is in range and on target.

claidemore · 03-05-2008, 11:35 AM

Renrich: no misunderstanding bud, just wanted to contribute some numbers to the discussion.

I like numbers, they are the ultimate weapon against colorful rhetoric.

Cheers!

kool kitty89 · 03-05-2008, 02:33 PM

I totally agree that 4x .50 cal guns would have been better for the BOB. (plus there would likely be a longer firing time). They probably could have used 6x .50's but that might put a penalty on climb, and ammo load. (particularly important for an interceptor)

It would probably take a 4 sec burst with decent aim and positioning to down an average twin engine bomber at the BOB as long as the pilot focused on the vulnerable areas of the bomber. (fuel tanks, engines, and -depending on armor- cockpit)

renrich · 03-05-2008, 05:29 PM

KK, obviously I have never engaged in ACM or any air to air gunnery but in reading about and talking to men who have engaged in practise shooting at a sleeve and in looking at gun camera film it looks to me, that for most pilots, putting a few bullets into the target anywhere is about the most they can hope for. In other words, shooting at a specific part of the enemy AC is beyond the skill of most pilots.