Warbird Information Exchange

Battlerabbit has raised an old subject, which I thought might interest many. If you are new you may want to read the original one, lot's of good info there. Warning, As a Spit owner some would say I may be biased(nah!) but I try to give at least an informed opinion. Also one crazy Aussie(is that redundant?) sleeps with a picture of a Beau (not a beau) under his pillow. Here goes.

MOST IMPORTANT: Probably the ME109, front line fighter from before the war until the end. Was the late FW190 better? The top guys Hartmann, Rall, stayed with the 109 as a high alt fighter. Even in 1945, in the best 51D, Jug, or MKXIV Spit, the 109 was still a competitor when flown by one of the real vets. Others may say the YAK(more built than any) and I am not an expert, but don't think Russia was as dependent on fighters as on their army and tanks. Germany would have been lost without the 109, as they found out when they tried to send Stukas, 110s, etc. over England. Eventually the P-51 became the vital fighter as a long escort. But the 51A was inferior and the Merlin 51 not a factor in the first 3 years of the warllllll

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Bill Greenwood
Spitfire N308WK

If one limits this to Battle of Britain, perhaps the Hurri, there were about 60% hurris and 40% Spits. The strategy was Hurris attack the bombers, Spits as top cover. Jerry did not always make this easy. The kill rates were around 60/40 (so I have read) in proportion to the numbers involved. BUT once place the Spit stood out was in better survival rates once in combat, probably because it was a little faster.

If we go on through the war there is no comparison. Spitfire development continued all those years and all those models. More speed, more armament, higher ceiling. At the end of the war the Spitfire was front line and pretty much the equal or superior to any fighter in service in real quantity. Except for a big range bonus, a 51 D has nothing equal to a MkXIV Spit. I am not sure when the last Hurri was produced, but it is not in the same tier as the late Spit., Mustang, 190 etc. The last Spits, the 20 series and the Seafire 47, are among the highest performance piston fighters ever. The ultimate development, the Spiteful is the fastest, highest performance piston fighter of all, even if not exactly user friendly. Too bad none exist now.

Guys I don't want to sound like yo Mama, but this part is about which is best Spit or Hurri, as per the question from Battle in the other forum. It has nothing directly to do with how good the 51 is, nor how good any pilot is nor, Randy in the F-15. Those are other good subjects, but not this one.

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Bill Greenwood
Spitfire N308WK

I am not that expert on guns. In the earlier forum, K5083 had data on the major types. He had rate of fire, muzzle velocity, range, weight of bullets, etc. A 303 has a high rate of fire(also reliable) but the bullet is small. Next up is a 50 cal, then more still the 20mm cannon with faster and heavier shell but at a slower rate of fire. So which is best?

RAF fighters started with the Browning .303, essentially a automatic deer rifle. It was fast firing, and very reliable, also light weight and small. For someone as good as Bader, a Hurricane with 12 guns or even 8 was deadly. As the war grew, RAF tried 20mm cannons to penetrate German armor plate, to have explosive shells, and to have longer range and more hitting power, and to counter the cannon in 109, and Zero, etc. Reliability was awful at first, they jamned. Most Spits IXs had a blend of 2 cannon and the 303s; XVI had 2 cannon and 2 American 50 cal. It was pretty clear the .303 alone were not good enough, and likely a weakness of the Lanc.



Along comes the 50 cal American heavy machine gun. It also has teething problems, jams and is not as reliable as a 303. But it has more range and hitting power, it fits in between the 303 and the 20mm , and becomes a very good gun for the 51, Jug etc. It is heavier than a 303 but not so big as a cannon.

So which is best? The RAF were air combat experts, and they pretty much settled on four 20mm cannon for the late model Spits etc. The Mustang did well with 6 50s, they even sufficed in Korea on jets. But in the end I think cannon are proven best. I don't know of a modern jet fighter that uses a machine gun instead of a 20mm or 30mm cannon. Evolution Has Gone to the Cannons.

A question could be, if 50s are good, but cannon better; then which of these is best? A 51 with 6 50s, versus a Spit with 2 20mm and machine guns, or a P-47 with 8 50's vs a Spit with four 20mm cannon. And guys this is about guns vs cannons, NOT which pilot is best or how good some other type is . This is the question someone asked and I am trying to answer.

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Bill Greenwood
Spitfire N308WK

This debate has some wide open parameter's, and agreeing with Bill could become downright unhealthy. First, let's tighten a bit. That spit w/4 hispanos in the hands of a top pilot was (I believe deadlier than, and a better pure fighter than the P-51) i.e speed, climb, dive and maneavure.
However, that 51 in the hands of a top pilot was no slouch either. The Hispanos are still being used today in some aircraft, and the browning of 1919 fame soldiers on even today with our ground forces. A 20mm strke on a 51 would prove deadly almost anywhere, a 50 cal on a spit is mostly survivable (advantage spit) But isn't this debate more advantageous to the ability of the pilot, regardless of airplane?

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tracers work both ways

Bill: It really depends on two interlocked things....what is the particular target and at what range are you trying to kill it?

Small, fast firing weapons with lightweight projectiles are great for chewing up and shredding large surface area targets at low speed and fairly close range. It's like going after something with a shotgun. You hit it with enough small projectiles and you will induce some kind of a failure that results in the loss of the target.

On the other hand, a large, slower moving, heavier round works better at longer range against hardened, or densely packed targets. A 20mm going through the engine cowling is going to be making a huge hole and displacing a lot of material when it does. The odds are that even if it doesn't result in an immediate failure, it will inflict enough damage that there will be a failure in a short time.

Get too close to the target or go against a lightly packed one, and most of the projectiles are going to do little more than drill large diameter holes through the target. Only by pure luck of where those holes are drilled, will the projectile impact something significant and cause the destruction of the target.

There are numerous good examples of this out there...a couple that I can think of right offhand..

P-47's with jugs blown completely off engines by cannon fire, but were able to make it home or to a safe landing.

A P-47 with a 20mm round going through a prop blade resulting in a hole larger enough to pass a football though. Aircraft landed safely.

A PBM from VP-74 took an 88mm round from a sub deck gun though the right front door mooring grip. Round exploded in the the radio compartment wounding the operator and large pieces of shrapnel exiting the cockpit floor and the step in the hull. Aircraft had no real structural damage, but nearly sank on recovery due to the huge rip in the hull at the step..( This one was family and in some of the stuff in storage, I've got a bunch of the pictures shot during that mission and recovery).


On the destructive side, I've seen both stills and movies of things like B-26s getting wings knocked off by cannon rounds, heavy bombers shredded by light gunfire, some surviving and some not..

By what I see, the best is really a combination of weapons that have selective firing capability so that you can select what weapon and what firing rate is going to be the best for the target at that particular instant.

Randy and the others that are trained to do this and are able to make the snap assements and rapid physics analysis can elaborate more or better, as they do this stuff and stay current on what is really and truely happening in the combat arena. Sure I mess with fighters daily and have done so for years and can do a lot of the mental gymnastics to make the shots, but those guys do if for real and for keeps. When I make a mistake out playing around, it's "Aw shucks, you got me", and hopefully we all go home and have a good time that night. With the guys that do it for real, a mistake means that most likely someone isn't going home from the mission that should have and it will probably have been fatal.

My hats off to those guys, as it takes a heck of a lot of skill to yank 25+ tons of aircraft around the sky, manage everything in the cockpit, do the mental work required to make the shoot decision, and at the same time keep track of where he is, his wingman is and where the enemy is at too, and then try to stay at least one step ahead of them.

I just read one of the stories in Col. Ken Chilstrom's exellent book, "Test Flying At Old Wright Field". This story was about an incident that occurred while Ken was test flying a captured FW-190 at Wright Field in July of 1944.

I Was fortunate enough to run into Col. Chilstrom at the NMUSAF on Oct. 1 of this year. We talked for a bit about his interesting military career and his varied flying experience.
For any of you that missed my earlier post about Ken Chilstrom I will briefly describe his credentials. Ken flew 80 missions in A-36's with the 27th Fighter Bomber Group in the North African campaign, then returned to the states in 1943. He was assigned to Wright Field as a test pilot and graduated from the very first test pilot class along with other notable pilots such as Dick Bong, Tony Levier, Bob Cardenas, and Glen Edwards.

At Wright Field Col. Chilstrom flew most of the captured enemy (and allied) aircraft that existed, during his test pilot duties. In Sept. 1946 he was chosen to be Chief Pilot of the Fighter Test Division at Wright Field.
During his Air Force career Ken Chilstrom flew 147 different aircraft!!

In his book mentioned above Col. Chilstrom makes the following statement....."I have often expressed my opinion that the three best WWII fighter airplanes were the Spitire, the P-51, and the FW-190".

This comment by Mr. Chilstrom is not directed specifically towards gunnery capability, but is more accurately his opinion of the aircraft in general.


Ted

How about stepping outside WWII(just a smidgen) and comparing the Bearcat to the Spitfire. I have always been of the understanding that the bearcat was designed using the Mustang and Hellcat as benchmarks to exceed. Also, what of the corsair? It continued on after WWII, and during the war had an astonishing kill rate (11 to 1).

Other than those two, I think it may be time to concede victory as the ultimate piston fighter to the later model Spits.

Also, don't count the Allison powered P-51A out either. If you are talking high altitude then yes, it was over matched due to the Allison's limitation at higher altitudes.

At lower altitudes the P-51A was easily a match for anything it went against. Remember...the first American ACE in a Mustang was in an Allison powered A-36.

I would also put forth that the later in-line engined FW-190D (and to some extent the Ta-152) was a much better and capable aircraft than the ME-109, even the later "tall-tail" version of the 109.

Battlebunny, re the Bearcat, Unfortunately I haven't flown one. Howard tells me how easy the F8F is to fly, but when I ask for a go, he says I can't handle it! A Marine for ya! It has a big following, but it is all speculation as it never flew in combat, not even Korea, just some dive bombing not too well for the French, in a delightful little place in the east. It has the best climb of anything even a Spit, it is very fast low and pretty fast up high. It has higher wing loading so I think a Spit will out turn it, and the Spit might have a little more performance at top altitude. Nothing out breathes a Rolls. In civ use pilots love to fly them, they also have enough fuel, land short. They are however, hot and dirty. One of the 3 planes I'd most like to try. I have not flown a Hellcat. Steve Hinton told me it would give a Spit a run for the money below 10,000 feet. A Spit. is a lot faster above 20,000. One of the problems in comparing kill ratios is different circumstances. By the time Hellcats got there the Japanese pilots were no longer well trained, cept for a few vets, and support(fuel food, medical, intel) were not as good. The early P-38 was mauled by the 109s. Later it did well at low altitude against the Japanese. The Corsair has a lot of supporters. But it is late war Pacific. It wasn't there in the Battle of Britain to evaluate against Germans. Gunther Rall told me how easy it was to fight the Russians at first. Anf also in my original topic the parameters were for more of a dogfighter. The Corsair was used for ground attack in Korea, only considered as a minor asset in the original discussion. Hey, get one of each, and call me to fly them.

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Bill Greenwood
Spitfire N308WK

Bill-

On the face of it your question seems straight forward... which is a better gun... a fast firing small caliber, a fairly heavy slower firing machine gun, or a slower firing cannon. The problem is how do you compare the lethality of a particular weapon in any equitable way... how do you make it an Apples-to-Apples comparison?

The way you figure lethality has been adequately expressed by Robert Shaw ("Fighter Combat"). Lethality is a function of Weight of Fire (actual weight of the round x Rate of Fire) times Muzzle velocity.

For a US 30 Cal M2 the weight of fire is 25 lb/min, muzzle velocity is 2,600 ft/sec.... resulting in a lethality factor (Fl) of 1.7... I'd hazard a guess that this is very close to the British 303.

A US 50 Cal M2 results in a Fl of 6.4.... a 20MM Cannon has a Fl of 15.9.

So lets compare the results:

Spit (4 303s = 6.8, 2 20MM= 31.8 ) 38.6
P-51 (6 50s) 38.4
P-47 (8 50s) 51.2

Now, that seems to be an even comparison between the Spit and the Mustang... trouble is that the 303's all together are equal to one 50... and the odds of getting all those rounds into one hole are miniscule (dispersion is a fact of life)... and the cannon has a rate of fire a little more than half the machine gun... if the round gets there it does lots of damage... if it gets there.

The answer to your question is that the 50's were head and shoulders better than a small caliber gun combined with a slow firing cannon. They always put the rounds where you wanted them and a couple of rounds were lethal (with some harmonization issues for wing mounted guns... the P-38 concentrated all the fire in the nose... very easy to point and very lethal). The muzzle velocity of the WWII era cannons was on par or slower than the 50 cal... in Korea the Jets could... and did... over run the bullets they fired... not a good thing... you need faster muzzle velocity...

The trick is how do you get that cannon round out of the gun in large numbers at high speeds... as a comparison the M61 Gatling gun... a 20MM weapon found on the F-15/F-16 racks up a Fl of 144.8.... pretty impressive... a rate of fire of 6,000 rounds a minute at a muzzle velocity of 3,300 Ft/Sec. It is the gatling gun that makes the difference.

I was never overly concerned about the cannon's on the Migs (they are known as chain guns... single bore weapons)... the rate of fire was SO SLOW (Lethality factors on par with WWII)... in a knife fight the M61 is a better weapon... a Gatling gun is NOT as much a cannon as it is a very fast large bore machine gun.

A gun kill is the best kill... and with the new PGU-28 bullet... well it's just way cool.

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Scott 'Gunny' Perdue
www.flyAMT.com
www.scottperdue.com

Scott, good figures. That is one way to look a guns, wt.xspeedxrate. If we use that formula, it shows an 8 gun Spit totals 14, 12 gun Hurri= 20, 51B =22, 51D=32, Spit IX=39, P-47=43, P-38=53, Spit XIV=64. I hope I got the math correct, you can check it. Remember the question from Phil 65 was Why I think cannons are best. It wasn't about which plane had best guns. I think these figures agree with what I said and most of all the direction the RAF evolved. Conclusion: The 303s, even 12 are pretty light as are 4 50s. Both the 6 50s in the D and the cannon/303 combo in Spit IX are pretty good. The Jug is effective, the 38 more so and the Spit XIV even more so. Your post did not include the 4 cannon Spit.

This is a good math way of looking at arms. But there are others. For instance how much a bullet drops over distance. I know a 20m drops less than a 303, I assume it drops less than a 50 cal., so easier to hit a target. Also other factors such as the weight of the guns and ammo. I don't have data on that.

Another big factor is penetrating power. A cannon has more of this, plus explosive rounds, so it isn't the whole picture to say a lot of 30s or even 50s is equal to a few cannon, even if the total is. Just as in car racing, hitting the wall once at 200mph may do a lot more damage than a number of impacts at 75.

I don't know about jets overrunning shells. I think a 20mm is a faster bullet than a 50 cal. Cannons were in Me 262 as well as Migs. The British 20s had a faster rate of fire and more velocity than the 109 cannon.

So I believe the best is 4 cannon which is what RAF settled on. Lot's of modern fighters use cannons, I don't know any with 50s.

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Bill Greenwood
Spitfire N308WK

Connery, the question I picked the 109 on was which was Most Important fighter. The FW was not around in the early years, nor used in the numbers as the 109. And even at the end of the war the top aces, Rall, Hartmann did not switch to the FW. So don't sell a 109 short.

As for the 51A, like the P-40 it was fine for its time. But if it was really that good it would not have changed so quickly. Why do you think the Brits put the Merlin in it? In the early form it had decent speed down low. But the Germans came over England at 20 or even 25,000 feet, well above the effective altitude for an Allison. Later at 25 or 30,000 feet the 109s would have mauled them as they did the P-38s.

A good pilot may be an ace, like Joe Foss, Bader, etc. in an early model. It doesn't mean the plane is on a par with th later fighters.

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Bill Greenwood
Spitfire N308WK

Bill-

You are looking at the issue as an engineer would... not a fighter pilot. A gun shot is a difficult thing to achieve... and very fleeting. What you want from your guns are a fairly high rate of fire, heavy rounds... lots of them at a predictable range. The WWII cannons just didn't cut the mustard... 50 cal machine guns were much better... one way to judge that would be to compare the number of multiple kills per sortie. It takes more rounds from a lighter gun... and MORE time with a 20MM cannon... luxuries not always available.

As regards the drop of the round... it is somewhat a function of muzzle velocity (somewhat also a function of the shape of the round)... but regardless every round is affected by gravity the same (16' drop in the first second)... the WWII 20MM cannons were equal to or slower than a 50 cal machine gun (the Brit HS MkII/IV was 100 ft/sec slower than a 50 cal with a rate of fire 2/3ds of a 50... the German cannon was nearly 1000 ft/sec slower with a rate of fire 1/2 of a 50 cal). In 1953 the US developed the M39 20MM cannon from an experimental German gun... it used a rotating cylinder like a revolver to up the rate of fire and the round had a much higher muzzle velocities. The M61 Gatling Gun came along in 1957... with the M52 round it has a dispersion of about 8 mil at 1500'... with the PGU-28 round it is uuuh much less... if I told you I'd have to kill ya<g>...

A larger round at the target is desirable... but to be useable it has to get there fast... with lots of its buddies. In WWII the Germans used the cannons primarily for the bombers... against a maneuvering fighter a cannon of that era was just not as effective as harmonized 50s. A lot of the present day fighters have guns that engineers like... but not pilots... gimme a M61 any day...

So the real answer to your question is time/target dependent.... in WWI the best combo seemed to be 2x 30 cal firing synchronized through the prop... in WWII against fighters 6x50 cal wing mounted / The German cannon gun combo was effective against bombers... in Korea the Migs used cannons, the F-86s used 6 50s (the kill ratio was better than 10-1 in favor of the F-86)... now we have the M-61 gatling gun for US type fighters against 30MM chain gun equipped Migs/Sukhois.

Evolution is the name of the game...

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Scott 'Gunny' Perdue
www.flyAMT.com
www.scottperdue.com

Let me refresh your memory. In the last air-to-air combat in History between two opponents flying props., it pitted a Honduras Air Force F4U-5 ( With 20mm ) against a Salvadorean Air Force F-51 ( Shot down and pilot KIA ) and the same HAF pilot and aircraft against two salvadorean FG1-D ( Both shot down, 1 pilot KIA ). All these in the 100 Hours War, July 1969.
On a one-to-one basis, my guess is that it takes a combined effort from man and machine.( The 20mm won´t hurt either !!! ).

Corsairdude-

There you go mixing apples and oranges... I thought the topic was guns... in fact the man in the machine makes up a larger portion of the equation for who will be successful in any particular engagement (for example the training for American pilots was probably the bigger reason for the success of the F-86 in Korea, although a large number of the opposition there were Russian)... but it is not the same topic as guns.... your bias is obvious<g>... for me if I had to be in a knife fight for real I'd prefer an F-15... If the discussion is limited to WWII and I were to be purely offensive I'd prefer the P-38... but I'd hate to fight it defensively... but how does that fit into a discussion of guns?

gunny

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Scott 'Gunny' Perdue
www.flyAMT.com
www.scottperdue.com