Ammo and WWII planes


Many WWII bombers had greenhouse cockpits and other window-like protrusions. Which material was used for “glass” and how easily was it broken? Was there any special ammo for that or just regular ball would do? Or did the planes carry regular ball at all? Here is the star of the movie “Memphis Belle” as an example of this type of “glass”.



The windows on aircraft of that era were made of plastic, “Plexiglas”.
Today Plexiglas often used as “bullet proof glass” in banks and gas stations.
But that stuff is 2 to 4 inches thick, while the stuff used on WWII aitrcraft was only 3/8 to 1/4 inch thick.
A 30-06 or 8mm would punch a hole thru it real easy.


On airplanes as large as multi-engine bombers with crews of ten bullet-proofing the windows (excepting perhaps the pilot’s windscreen) was out of the question and essentially useless. The only bullet-proofing on these planes was armored seats for the pilot (in some cases) along with some selective fitting of armor plate and self-sealing fuel tanks (again, in some cases). Crews sometimes wore flak-vests and steel helmets. In fighters, however, armor plate was often employed around the pilot and the windshield, especially later in the war, was of very thick material (3-4 in. or 100 m/m), the composition of which is not known to me. Jack


Not to forget some tail gun turrets which had very thick layers of glass/pelxiglass also.

I remember a WWII image of a B24 which had impressions of 20mm HE shells on the armored glass of the tail turret, impressive image.



That Memphis Belle is a beauty. The plane is nice too!



Question, did the planes eject the fired cases from the gun turrets ‘over the side’ or were they dropped into some holding bin?


I had a cousin (Mother’s 1st) who served as a tail gunner, either in B-17s or B-24s over Europe. After a few evening drinks he would tell stories about the hot shells from the guns he fired burning his neck. He said they would get around his mask and burn him so I assume at least some of the shells stayed in the plane.

I have seen at least one photgraph where they were inspecting a damaged bomber and the ground underneath the plane was littered with brass, which I assumed had come from inside the plane as they cleaned it out.


I don’t know if any “holding bins” were used.

The chin turret on the B-17G, the tail guns, and the ball turret dropped the fired cases overboard:

Nose guns, waist guns and the rear top gun (and maybe the top turret guns) dropped fired cases onto the floor of the aircraft:

More B-17 guns @ 2:00-3:00 in:


A dear friend of mine “Freddie” was a door gunner on a B-17 “Melancholy Baby” and not only did he tell me incredible stories of 2000 planes heading out on a mission, but I saw photos of him “lounging” on a pile of expended 50 cal shells (smoking a cigar…celebrating the fact they were one of the lucky planes to return to base). He had commendations (I saw what looked like a “postcard” for each five flights they accomplished) for flying an unheard of 25-30 missions (don’t remember the exact #)…most planes only made a handful and met a bad fate.

Bottom line…as I know it…the expended shells laid in the plane (in piles)(at least at the doors)…I think it would be bad for the 100’s of planes to be raining spent shells down on each other…yes ?


Well Pepper your last sentence sums up my point of concern. We live about six miles away from the RAF Museum at Hendon and having two small sons, now not so small, and given that it was free you can imagine we were frequent visitors.
They have at least one gun turret you can sit in and imagine what it must have been like. Apart from the fact it was tiny I came away with two other mental images.
One was the exposed rotating mechanism on the floor that in my mind could all too easily get jammed up by fired cases.

The other was two rather primitive shutes basically bent metal to funnel fired cases out into the wide blue yonder.

Now try to form a mental images of planes flying on the thousand bomber raids late in WW2. Planes flying high and to the front would be shedding cases into the path of those planes flying below and behind them.
Cartridge cases falling several hundred feet and then hitting a plane flying at a couple of hundred miles an hour could do a lot of damage.

In the garden of my parents house in NW London when I was a kid we dug up a fired German MG case that had presumably fallen from a plane. Nobody thought it was remarkable. It sat on the window ledge in the garage for many years but then it disappeared. Presumably my father grew tired of it and binned it.


It wouldn’t be good, but it appears to me that it wasn’t a great concern. All fighter aircraft let their expended cases fall to earth, and as I noted previously, on bombers, those guns situated where it was feasible to jettison fired cases “into the blue” (chin turret, belly turret, tail gun), did so. At the other positions (top turret, nose and waist guns), ejection overboard wasn’t a practical option.


The modern 30mm Aden cannon on the British Harrier aircraft ejects its fired cases overboard. However the 27mm Mauser cannon on the Tornado retains the cases on board the aircraft. I used to have an Aden case with part of he rim torn off where it looked to have impacted hard ground. With the damage done to the case giving an idea of how hard it must have come down, I certainly wouldn’t have liked to have been underneath the aircraft when it was fired.


There are several reasons why empty cases, and steel MG belt links, may be dumped overboard or retained on the aircraft. Where practical, disposing of the empties gives advantages of reducing aircraft weight and reducing the chance of the scrap metal jamming something important. However the discarded cases and links pose a hazard to other aircraft nearby and sometimes to your own aircraft. Some fighters are severely damaged by their own cases/links, it just depends on what the airflow does. In these planes there is no choice but to bring your empties home.



“Chain Guns” and similar type of High rate of fire Machine Cannon in Aircraft usually are fitted with “pods” for the ammo belts chains, and they come back to landing with these Pods filled with the empties… Vulcan type (Gatling) and all the Russian Guns use the “shoot it and loose it” technique, by chutes to the outside.

These days the “falling debris” situation is not a concern, as there are fewer aircraft in the air during a “raid” than was common in WW II.

The other danger from 1000-plane raids over Europe was that they also carried 44gallon Drums of extra Avgas, for the outward trip…so the Main Tanks would be full for the return ( or almost)…Empty Gas drums were usually jettisoned before arriving on Target, and the Poor Villagers below could get one through the roof etc…It happened at my Mum’s place in Northern Italy, 1944…a 44gal Drum came crashing thru the Tiled cover of the Water Well, smashing it completely…on the good side, my maternal grandfather got a slightly dented, Heavy Duty USAAF petrol Drum, which he used in his Building Business.

One must remember that Fighters also jettisoned their auxiliary fuel Tanks as well, whether full or empty, over enemy territory, as the need arose.

In the days of Rifle calibre MGs on Planes, the problem of “spent cases” hitting other planes or the ground was minimal. but with the heavier Cannon cases, there was a Real problem…

Planes also jettisoned even their MGs (B17s) if damaged whilst returning Home to UK…to lighten the load…

Doc AV
AV Ballistics.


I have all the original WW2 manuals for the B17 that my Grandfather left me. I will take & post pictures and info on the Nose-cone material and fabrication from it. Also, the diagrams show a dedicated “Ammunition Case” shoot in the tail gunners position to eject spent cases and links. :-)



Doc, the only Chain Gun I know of installed on aircraft is the 30mm M230 under the AH64 Apache attack helicopter. This uses a linkless feed system.

It’s the Gatling-type 20mm M61 and 30mm GAU-8 which have the huge helical drum magazines and a linkless feed system which carries the rounds by conveyor to the gun and carried the empties back to fill up the drum. Some of them have a “reverse” mechanism so that at the end of a burst, the unfired rounds in the gun are automatically fed back to the drum.

An historical note: the RAF discovered with their new Hawker Hunter fighter in the 1950s (which initially ejected both fired cases and belt links overboard) that the belt links were being blown back against the aircraft, damaging the skin. So they built big bulges under the gun breeches, specifically to hold the links (the cases weren’t a problem, they dropped clear).

I am really struggling with this one, Doc. They carried fuel drums on board the aircraft, and manually refuelled it while in flight? I have never heard of such a thing, and find it very hard to believe. More information please!

[quote]Planes also jettisoned even their MGs (B17s) if damaged whilst returning Home to UK…to lighten the load…
They could do even better than that - the entire underfuselage ball turret could be jettisoned in flight.


As a boy during WW2 living near an Army training area on the Sussex downs, I soon became familiar with .303 and 9mm cartridges, but my first contact with larger calibre stuff came in 1944 when I found a belt of about a dozen rounds of 50 cal cartridges sticking bullet-first in the ground. These had clearly either fallen, or perhaps more likely been jettisoned, from one of the hundreds of B17s that flew over us almost every day on their way to and back from targets in Europe. I remember there were a few red-tipped rounds present, and I believe black also but I don’t remember exactly, and I’m ashamed to say I can’t recall the sequence!

John E


There was an article in the Britain at War magazine in summer 2008 by someone who had found a 1913 dated German Machine Gun (I can’t remember the type). He had pulled it out of a river when he was at school in the 1950s. He believed it could have been jettisoned by a Zeppelin as they apparently did fly over the area during WW1. However, unfortunately the school headteacher got wind of their find and the police took it away.


Just went threw 1000+ page manual on the B17 and took a few pictures.

This text explains the nose material

Thought this was cool.

There is a dedicated port for ejected ammunition cases for this gun

#25 shows the port on the belly view

I think Pepper is right that the spent cases stay loose in the plane for the side 50’s. I found no mention of a storage system or ejection system in the manual at all.


Took a pic of the book, GUNNER, An Illustrated History of World War II Aircraft Turrets and Gun Positions.

Maybe not definitive, but does a fine job covering the topic in pictures and text. Lots of pics. Over 20 plane’s gun positions detailed. Good stuff.

Copyright prevents me from showing more.

Just checked on Amazon. They’ve got this, in paperback, for less that $10. The “collectable” edition(Hardcover) is $25.