Ammunition Link and Complete Round Weights

[Ivan1GFP]

Hello All,

I am looking for ammunition and link weights for the common aircraft machine guns and cannon of WW2.

Information on American guns is not hard to find. Anyone know of a source for guns of other nations? The purpose is to calculate the disposable ammunition loads for various aircraft.

Thanks
- Ivan.

 

[Ivan1GFP]

Japanese Type 89: 7.7 x 58SR
Complete Round + Link: 34 Grams
Source: A6M3 Weights Data Sheet - Courtesy of Shinpachi!

Japanese Type 99-1: 20 x 72 RB
Complete Round + Link: 375 Grams
Source: A6M3 Weights Data Sheet - Courtesy of Shinpachi

German MK 108 Cannon: 30 x 90RB
Complete Round Weight: 480 Grams
Complete Round + Link: 595 Grams
Source: Schiffer Focke-Wulf - Kurt Tank Aircraft Designer Book.

British Browning .303 MG: 7.7 x 56R
Complete Round + Link: 1.06 Ounces
Source: Hurricane Mk.II Manual

British Hispano 20 mm cannon: 20 x 110
Complete Round + Link: 10 ounces - I believe this is a bit too low.
Source: Hurricane Mk.II Manual

German MG151/20: 20 x 82
Complete Round + Link: 199 Grams
Source: Schiffer Focke-Wulf - Kurt Tank Aircraft Designer Book.

- Ivan.

 

[Shortround6]

Something seems a bit off on either the Hispano weight or the the Japanese Type 99-1 20mmX72 weight. While the projectiles were either the same weight (or within a few %) the shorter, smaller diameter case and lighter powder charge of the 20mmX72 should mean it is a lighter complete round. Unless the Japanese are using really, really heavy links.

Weight of ammo alone for a variety of guns can be found here.

WORLD WAR 2 FIGHTER GUN EFFECTIVENESS

If you know the weight of a few different sized links reasonable assumptions should be able to be made for others.

 

[Ivan1GFP]

Hi Shortround6,

I found that site a while back and I took some of that information into consideration. I was pretty sure that sooner or later, someone was going to comment about the inconsistencies of what I posted. A lot of the data I found was quite inconsistent which is why I only posted some of what I found along with the source.

The weight of the Hispano 20 mm round seems way too low and I left a comment about that, but that is exactly what I found in the Hurricane II Manual. I believe the 20 mm used by the USA is the same gun and the ammunition weight is much higher in the book America's Hundred Thousand by Francis Dean. The problem with that data source is that even for a .50 Cal Browning, the weight per round differs depending on which aircraft is being described which is why I didn't post data from there. Bullet and Link weights vary from 4.8 to 5.something ounces.

I am still looking.....
- Ivan.

 

[Shortround6]

Not all .50 cal ammo weighed the same. See: .50 Caliber Browning (12.7 x 99 mm) Ammunition

A difference of 4-5 grams between some bullets. the M8 API coming into much increase use form about 1943 on, late war it was a 50% of aircraft .50cal ammo used. depending on the mix of ammo in the belt the weight could vary a 1/2 pound easy and taken to extremes (100% lightest bullet vs 100% heaviest bullet) you might get a full 1 lb difference.

Some of the 20mm varied as much.

 

[Ivan1GFP]

I understand that different types of rounds weigh differently, but still, there is some kind of "average" or standard weight allowance. I am just surprised it differed between aircraft.

This is sorta like saying different pilots weigh differently as do parachutes, but the standard weight specification for a crew member on US WW2 planes was 200 pounds. Germans tend to be bigger and more buff as we know (=^>) so that explains why their crew weights were 220 pounds (or 100 KG). Japanese crew on the other hand only weighed 75 KG.....

- Ivan.

 

[Shortround6]

It may have something to do with timing (or it might not?) the lighter M8 API ammunition didn't exist as a service round for most of 1942 or early 1943. The specifications for the ammo load for a 1941-42 fighter would be based on the heavier ball and and AP rounds with perhaps a small percentage of tracer? in 1943 the specification might include a percentage of the M8 round (or not?) while by 1945 for aircraft use the M8 had displaced almost completely the the older ball and AP rounds. Tracers still being a percentage of the total load?

Now maybe this doesn't track with the figures you are finding, just throwing it out there as a possible explanation.

 

[Ivan1GFP]

Hi Shortround6,

Actually it DOES track with the service use of the planes. The P-51 and P-47 had lighter .50 cal rounds than a P-40.

Now to find more sources.....

Thanks.
- Ivan.

 

[Ivan1GFP]

Can anyone here summarise which guns used disintegrating link belts?
I know the US .30 cal and .50 cal and the British .303 used disintegrating link belts.

Thanks.
- Ivan.

 

[Shortround6]

I think most aircraft guns used disintegrating link belts.

Except for those guns that used drums or large guns that used and endless belt.

German MG FF cannon used drums, the MG 15 used a saddle drum. A few of the odd balls used drums or strange belts.

Japanese Oerlikons used drums to start, changed to belts later. A few of the 7.7 observer guns used drums.

I don't think any of the Russian guns used anything but disintegrating link belts until they got to 37mm or so and I may not be remembering that right.

Hispano 20mm started with drums but changed to disintegrating link belts.

I think the French mg used belts, they just put them in a container that looked like a drum.

Italian guns used belts.

People had given up on non-disintegrating belts about WW I. long strips of canvas led to too many jams.

Some really big guns used an endless belt in a housing but these are usually 37mm or bigger.

 

[Ivan1GFP]

Hi Shortround6,

I figured a way to find out MOST of what I was asking. I am doing image searches for belts for these guns.

Here is my conclusion thus far:
US uses disintegrating link belts in everything under 37 mm. 37 mm in aircraft was a 30 round continuous belt.

Germans used NON-disintegrating link belts in MG 17, MG131, MG151, MG151/20. BK 37 mm on stuka used a strip.
Dunno about MK108 or MK103 yet.

British Browning .303 used disintegrating links. Hispano cannon (at least in later models) used disintegrating links as well. They had nothing in between of consequence.

Japanese used disintegrating link belts in their fixed installations though flexible guns varied a lot.

Haven't check for the Russians yet.

- Ivan.

 

[Ivan1GFP]

http://www.cockpitinstrumente.de/img/Mun 3 Sammlung MK 103 108 131gross.jpg

That "Link" shows a couple belts of the ammunition we are discussing. Looks like the MK 108 and MK 103 both use non-disintegrating link belts.

- Ivan.

 

[TonyE]

No, both the Mk103 and MK108 used disintegrating belts.

Also do not forget the British aircraft Vickers guns which used disintegrating links. There were three marks of links starting from 1917.

Regards
TonyE

 

[krieghund]

Mg17 belt of 500 rds weighs 32.5 lb.
MG131 Belt of 100 rds weighs 18.7 lb Belt length is 7 ft 10 in
MG151/15 Belt of 100 rds weighs 37 lb.
MG151/20 Belt of 100rds weighs 43.75 lb.
MG/FF 20 Drum weight -- 60rds/44.75 lb. (empty=18.08 lb) -- weight of complete single cartridge = .445 lb, empty cartridge = .117 lb, projectile=.295 lb

 

[Ivan1GFP]

Thanks Krieghund,

That is very useful information. The idea behind this exercise is to figure out how much weight an aircraft loses when it fires off its load of ammunition. The disintegrating link belt loses the weight of a link with each round fired. The non disintegrating link only loses the weight of a cartridge.

TonyE,

Take a look at the photograph at the URL I posted. If the photograph has correct labels, it looks like non disintegrating link belts to me.

- Ivan.

 

[TonyE]

Ivan

The photograph is correctly captioned. Am I correct in thinking from your post that you have never actually handles these rounds and links? When the round is withdrawn from the link it allows the link to disengage from the next link.

The attached is from Chinn, Volume 3, Section 5, p.621.

REgards
TonyE

 

[Ivan1GFP]

I have handled .50 Cal M2 ammunition and 20 mm. I have not handled ammunition from any of the German MG or MK. In the photographs, it looks like the links are crimped together and can stay in one piece even after the round is removed. Is this not the case? With the US ammunition, the round is the hinge pin. When removed, the links fall apart.

How do the MK103 / MK108 rounds hold the links together? I take it the round might be closing the open side of the hook?

- Ivan.

 

[TonyE]

The links unhook. The curved tongue fits into the slot on the next link and the round prevents them coming undone. Once the round is extracted the links are free to seperate. Unfortunately, as I don't collect German ammo I no longer have examples to photograph.

If you don't have a copy of Chinn, which is without doubt THE authoritive source on machine guns and cannon, it can be purchased very reasonably as a CD on the net.

Regards
TonyE

 

[Ivan1GFP]

Thanks TonyE,

I found a few images of the links (rusted a bit) on eBay. I don't know that I would actually try to get the book by Chinn. I only have a bit of interest as far as it affects the current project. I have LOTs of books already so it is a matter of choosing carefully. (Yes, I know this is a CD.) The depth that such a work would present isn't really needed for what I am trying to do.

- Ivan.

 

[krieghund]

Hi Ivan, I ran across one of your posts from 2008 asking for the CFS 1% Gun tables....I found them at last and here they are!!!