Author Topic: A look @ the Ho-103 the US 50cal and 2 others (Read 2435 times)

brady · « **on:** January 04, 2001, 04:17:00 PM »

The Ho-103 was basically a copy of the browning 50cal MG , but not an exact copy, it was lighter had a higher rate of fire a slightly lower M/V and it fired HEI rounds as opposed to your basic ball ammo of the 50 cal MG.The Ho-103 load out would most likely of consisted of 1 AP/tracer round followed by several of the HEI rounds and another AP/tracer....and so on. At this point a question arises

oes HTC factor in the explosive potential of HEI rounds on aircraft?, and do they do it for the weapons that fired them in all calibers? All of the Japanese Aircraft MG's fired a similar mix of rounds even the One's in our Zeros MG's (see bellow)
And does not the destructive potential of these rounds ,and the Higher rate of fire, make for a potentially more destructive weapon in the Ho-105, when compared to the US 50cal MG?

Ho-103: 900rpm,796M/S, wgt 22Kg

50cal: 750rpm,870M/S, Wgt. 30Kg

MG 131: 900rpm, 730M/S, Wgt 17Kg

Type 3:800rpm, 2,590fps, Wgt.66lbs

Type 2:900rpm,2,460fps, Wgt.37.5lbs

The type 3 is basically a 50cal MG although it fires a HEI round, the type 2 is basically a MG 131 firing the same type of ammo, also of note is the fact that the type 2 fires an active tracer(see bellow)which contains an explosive element.

Note: Italian 12.7mm ammo was of similar design.

Brady

(Please see bellow)

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[This message has been edited by brady (edited 01-04-2001).]

brady · « **Reply #1 on:** January 04, 2001, 04:23:00 PM »

Type 2 & 3 MG's:

Brady

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[This message has been edited by brady (edited 01-04-2001).]

Tony Williams · « **Reply #2 on:** January 05, 2001, 01:39:00 AM »

An interesting question, not easy to answer. The .50 fired significantly heavier projectiles than the Ho-103 (47g v c.37g) and with its higher muzzle velocity had a longer effective range and better armour penetration.

.50/12.7 calibre was very marginal for HE content to be worthwhile, which is why the US didn't bother with it, sticking with API. 20mm is generally reckoned to be the minimum for effective HE, particularly if you want to combine it with decent AP performance.

Having said that, I like the Ho-103. It is a good blend of compactness and hitting power. There's nothing wrong with the .50 M2 but it's a bit close in size and weight to a 20mm.

One thing I have learned about aircraft damage is that random effects are considerable; some aircraft survived massive damage, others were brought down by pinsalamanders (I have just read an account by a British infantry officer in N Africa, 1942, who got fed up with a Bf 109 stooging around him at low speed and altitude and fired a shot at it with his revolver. He hit the cooling system and the Messerschmitt didn't get back to base).

Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/

Toad · « **Reply #3 on:** January 05, 2001, 07:23:00 AM »

Quote

Originally posted by Tony Williams:
(I have just read an account by a British infantry officer in N Africa, 1942, who got fed up with a Bf 109 stooging around him at low speed and altitude and fired a shot at it with his revolver. He hit the cooling system and the Messerschmitt didn't get back to base).

Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/

Tony,

Not the dreaded "one ping kill"?!?!?!?

...and from a clearly OVERMODELED Allied Opportunist handgun?!?!?!?!

Vermillion · « **Reply #4 on:** January 05, 2001, 09:27:00 AM »

Brady, what book are you pulling these scans from ?

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Vermillion
**MOL**, Men of Leisure

brady · « **Reply #5 on:** January 05, 2001, 07:07:00 PM »

Mr. Williams said:

.50/12.7 caliber was very marginal for HE content to be worthwhile, which is why the US didn't bother with it, sticking with API. 20mm is generally reckoned to be the minimum for effective HE, particularly if you want to combine it with decent AP performance.

Ok, if the HE content was not "worthwhile" in this size of round then why did so many countries produce ammo for their guns in this caliber range?
A seemingly obvious answer might be that they wanted a lighter weapon, with lighter ammo, and since they found the hitting power of M2 50cal MG attractive, they decided to make up for their lack of kinetic energy in the round by giving it some potential energy to take with it.
Also as I understand it the Japanese idea behind what they wanted their aircraft cannons/MG's to do was a little different than the US theory. The Japanese wanted to "defeat the aircraft" as opposed to the US idea of kill the pilot destroy the Powerplant and the internal workings of the plane. Hence the US 50cal MG and it's ammo, punch hole's in the skin and punch hole's in ever thing in its path till it exit's the other side.The Japanese however were after the Plane, Blow great chunks of it away ,control surfaces, wings, set the plane on fire...

Vermillion, They are from TM-1985-5 Vol. I & II, Japanese explosive ordnance.

TM 9-2200, Small arms, light field mortars,and 20-MM aircraft guns

These can be found in a Federal Library, as I understand it they are in every congressionally district. The ones I have access to are In the Oregon Military Museum.Also their is a place where u can purchase Micro film of the Books I found it on the Net by doing a search for TM-1985-5.
This is the 5th book in the series , they cover all the countries in WW2.

Brady

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[This message has been edited by brady (edited 01-05-2001).]

Pyro · « **Reply #6 on:** January 06, 2001, 12:45:00 PM »

I have a couple of the manuals in this series including the one you've scanned. I sure would like to get the rest of them though.

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Doug "Pyro" Balmos
HiTech Creations

Tony Williams · « **Reply #7 on:** January 08, 2001, 01:57:00 AM »

Quote

Originally posted by brady:
Mr. Williams said:

.50/12.7 caliber was very marginal for HE content to be worthwhile, which is why the US didn't bother with it, sticking with API. 20mm is generally reckoned to be the minimum for effective HE, particularly if you want to combine it with decent AP performance.

Ok, if the HE content was not "worthwhile" in this size of round then why did so many countries produce ammo for their guns in this caliber range?
A seemingly obvious answer might be that they wanted a lighter weapon, with lighter ammo, and since they found the hitting power of M2 50cal MG attractive, they decided to make up for their lack of kinetic energy in the round by giving it some potential energy to take with it.
Also as I understand it the Japanese idea behind what they wanted their aircraft cannons/MG's to do was a little different than the US theory. The Japanese wanted to "defeat the aircraft" as opposed to the US idea of kill the pilot destroy the Powerplant and the internal workings of the plane. Hence the US 50cal MG and it's ammo, punch hole's in the skin and punch hole's in ever thing in its path till it exit's the other side.The Japanese however were after the Plane, Blow great chunks of it away ,control surfaces, wings, set the plane on fire...

I didn't say it wasn't worthwhile - just marginal. You have to remember as well that the two nations who produced guns in this calibre - Japan and Italy - were very late in providing decent protection to their aircraft. No doubt the HE 12.7mm would have been very effective against their own aircraft, but I can't see most US planes being very impressed.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/index.htm

brady · « **Reply #8 on:** January 08, 2001, 02:29:00 AM »

Mr. Willams said:

I didn't say it wasn't worthwhile - just marginal. You have to remember as well that the two nations who produced guns in this caliber - Japan and Italy - were very late in providing decent protection to their aircraft. No doubt the HE 12.7mm would have been very effective against their own aircraft, but I can't see most US planes being very impressed.

Irrespective of how well or poorly protected the aircraft of japan or Italy were or were not is I think kind of beside the point at hand. the effectiveness of their ammo on the "plane" is the question at hand, and I would think that the proprieties that would make their ammo effective against their aircraft would also make them effective against those of other nations,after all their ammo was tailored to attack the weakest element of the aircraft. The plane it's self, destroy the planes ability to fly, or be controlled and U have won the battle. punching lots of hole in a control surface with 50call ammo would have marginal effect, punching holes in the engine, pilot or fuel/cooling sys would.Blowing away the control surfaces with HEI rounds or setting on fire various parts of the plane would be effective, detonating HEI rounds on the armored seat of a US plane would not ne effective. So the moral to the story is both are effective in their own right.

Brady

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[This message has been edited by brady (edited 01-08-2001).]

Tony Williams · « **Reply #9 on:** January 09, 2001, 02:17:00 AM »

Quote

Originally posted by brady:
The plane it's self, destroy the planes ability to fly, or be controlled and U have won the battle. punching lots of hole in a control surface with 50call ammo would have marginal effect, punching holes in the engine, pilot or fuel/cooling sys would.Blowing away the control surfaces with HEI rounds or setting on fire various parts of the plane would be effective, detonating HEI rounds on the armored seat of a US plane would not ne effective. So the moral to the story is both are effective in their own right.

Brady

You're right in principle, the only point at issue was whether the little 12.7mm bullet could carry enough HE to blow off anything very much. Once you go for HE effect as the main destructive mechanism (as the Germans did with the M-Geschoss) then you're rapidly pushed into going for bigger shells as the gains are disproportionately greater.

I don't know how much HE the 12.7mm carried but most conventional HE shells had around 10% of their weight for HE, which would make the 12.7 around 3.7g. Compare that with 18-20g for the 20mm M-Geschoss or 85g for the 30mm. Note that the MG 151 first came out in 15mm, offering the advantage of very high muzzle velocity (and it was available with M-Geschoss), but this was rapidly dropped in favour of the lower-velocity 20mm version to get more HE punch.

To knock down a tough aircraft with 12.7mm HE (and the US planes were much tougher than Japanese ones, at least until late in the war) you'd need either to score many hits in much the same place, or get very lucky. I am not a noted supported of US weapons design but I think they got it right, in that API gave the best destructive mix in the HMG class.

In the postwar period Raufoss have developed 12.7mm Multipurpose (APHEI) projectiles which are very effective, but that kind of technology wasn't available in WW2.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/index.htm

Hooligan · « **Reply #10 on:** January 09, 2001, 09:45:00 AM »

German 13mm HE rounds and US .50 AP/I carried about 1g of HE or Incendiary compound. I very much doubt that any 12.7mm round carried much more than 1g of HE.

Hooligan

brady · « **Reply #11 on:** January 09, 2001, 08:51:00 PM »

Hooligan, which 50cal round are u referring to,cal .50 M1 , or M23 round?. Their being a considerable difference in the volume of incendiary material contained within them.

Brady

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[This message has been edited by brady (edited 01-09-2001).]

Hooligan · « **Reply #12 on:** January 10, 2001, 03:19:00 AM »

Brady:

The most common .50 round used in A/A during 1943 and later was the M8 AP/I. It contained 1.04g of incendiary compound.

Hooligan

Tony Williams · « **Reply #13 on:** January 10, 2001, 03:31:00 AM »

Quote

Originally posted by Hooligan:
Brady:

The most common .50 round used in A/A during 1943 and later was the M8 AP/I. It contained 1.04g of incendiary compound.

Hooligan

This was really a conventional bullet with an AP core and some incendiary material in the tip. I am assuming that a purpose-designed hollow shell in 12.7mm would be able to contain more HE (although I'm away from my sources at the moment).

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/index.htm

Hooligan · « **Reply #14 on:** January 10, 2001, 03:45:00 AM »

AGW:

The Germans were, to put it mildly, rather serious about HE, and since they only managed to get about 1g of PETN in their 13mm HE rounds I am assuming that nobody else did much better.

However, you clearly know a lot more about this than I do and I am looking forward to hearing what you dig up when you get access to your sources.

Hooligan