French incendiary 303


#1

Some info for the 303 collectors.

Here is a drawing of a French experimental incendiary bullet callet B5.

(B7, B9, B11 exist also).

The dashed line shows the shape of the plug before it was pushed into the bullet.

JP


#2

No drawing and no site shown on which it might appear.


#3

What ???
I do not understand !
JP


#4

It came up OK for me.

gravelbelly


#5

You don’t see it, John ??
JP


#6

John

Have you fed the squirrel today?? :) :)

JP

That’s an interesting bullet. It appears to be a bore-rider, I suppose because of the long cylindrical section.

Was the “air hole” leading to the incendiary mixture closed in some way before the bullet was loaded?

Ray


#7

[quote=“Ray Meketa”]JP

That’s an interesting bullet. It appears to be a bore-rider, I suppose because of the long cylindrical section.

Was the “air hole” leading to the incendiary mixture closed in some way before the bullet was loaded?

Ray[/quote]

Hi Ray !

What is a bore-rider ???

I have no more info. Only the drawing.

I cannot even tell you the date.
Before WWII, I am positive, but no exact year.

Frenchs made a lot of experiments with 303 ctges, during and after WWI.

I know at least 10 designs of French incendiary bullets.

Here is the drawing of the incendiary B7

JP


#8

JP

A bore rider is a two-diameter bullet or projectile. The front is bore diameter and the rear is groove diameter. The rear section is engraved by the rifleing and the front section “rides the bore.”

There are a several reasons for bore riders.

They allow for a very long bullet or projectile with a long cylindrical section (high ballistic coefficient) without having to cut a long throat in the chamber to accomodate it.

They result in less bore wear because less of the bullet or projectile is engraved by the rifleing.

They also result in lower chamber pressure and are also more accurate in some applications.

Small arms bore rider bullets are usually two diameters. Large caliber artillery bore rider projectiles can be 3 diameters. The driving band is groove diameter, the bourrelet is bore diameter, and the section in between is smaller than bore diameter.

Here’s a wildcat 25 caliber cartridge with a bore rider bullet. Very similar to that .303 bullet.

Ray


#9

Hi Ray !

Thanks for the explanation.

“They allow for a very long bullet or projectile with a long cylindrical section (high ballistic coefficient) without having to cut a long throat in the chamber to accomodate it.”

If it is not bore riderered the ballistic coefficient must be the same and even better without, I will say.(because no step in diameter)

"They also result in lower chamber pressure and are also more accurate in some applications."
Why a lower pressure ???
Why more accurate ???

Anyway all the Incendiary type B (5,7,9,11) are bore ridered !
Let’s try to find one which is not !

Here is an Incendiary type BC from 1922

JP


#10

The jacket on that looks extremely thin, therefore quite fragile. If the drawing is to scale it looks to be substantially less than 0.5mm thick. One wonders if it would actually survive being fired.

What was the incendiary composition in this bullet? I would be worried if I had any examples of the “BC” type incendiary today as corrosion of the extremely thin jacket could easily cause the compound to be exposed to the air and ignite, if it is that type of incendiary compund, and not one that is ignited when violently compressed on impact.


#11

“The jacket on that looks extremely thin, therefore quite fragile. If the drawing is to scale it looks to be substantially less than 0.5mm thick. One wonders if it would actually survive being fired”

Whre do you see 0.5 mm ??
I see 0.4 at the top which doesn’t touch the barrel and 0.7 + 0.4 = 1.1 mm at the bottom.

"What was the incendiary composition in this bullet?"
White Phosphorous.

I would be worried if I had any examples of the “BC” type incendiary today as corrosion of the extremely thin jacket could easily cause the compound to be exposed to the air and ignite, if it is that type of incendiary compund, and not one that is ignited when violently compressed on impact.
0.4 mm is thick enough I think.
Furthermore these ctges were not designed for collectors.
I will check as soon as I have time if the British Buckingham incendiary are thicker.
(And If they are not, I can tell you the answer: no pb.
Because I found a lot of them in the gound and they were all ok.
And I even shot a lot of them with no pb !)

JP

[/quote]


#12

JP

The worst thing you can do to a pristine bullet is shove it through a rifled hole with 60,000 psi of pressure. The violent acceleration and rotation, and the engraving of the bullet jacket by the rifling can only decrease the ballistic coefficient (BC), degrade accuracy, and raise chamber pressure. There are ways to minimize these bad things. VLD (Very Low Drag) bullets with their long ogives and boat-tails, slippery coatings such as Molybdenum Disulfide (Moly), shallow, multi- groove or ratchet type rifling, and bore-riders are just 4 of the many ways to accomplish this.

Ray


#13

[quote=“jean-pierre”]“The jacket on that looks extremely thin, therefore quite fragile. If the drawing is to scale it looks to be substantially less than 0.5mm thick. One wonders if it would actually survive being fired”

Whre do you see 0.5 mm ??
I see 0.4 at the top which doesn’t touch the barrel and 0.7 + 0.4 = 1.1 mm at the bottom.

"What was the incendiary composition in this bullet?"
White Phosphorous.

I would be worried if I had any examples of the “BC” type incendiary today as corrosion of the extremely thin jacket could easily cause the compound to be exposed to the air and ignite, if it is that type of incendiary compund, and not one that is ignited when violently compressed on impact.
0.4 mm is thick enough I think.
Furthermore these ctges were not designed for collectors.
I will check as soon as I have time if the British Buckingham incendiary are thicker.
(And If they are not, I can tell you the answer: no pb.
Because I found a lot of them in the gound and they were all ok.
And I even shot a lot of them with no pb !)

JP

[/quote][/quote]
The measurement “3.5” is shown across the nose of the bullet, and this makes the jacket look extremly thin. 0.4mm looks about as thick as the walls of a drink can on my vernier, which I would have thought could corrode very easily.


#14

Hi Falcon !
Yes it is a different concept.
With the Buckingam British bullet you have a small hole on the side closing the container with WP. This hole is filled with a special lead alloy with a low melting point (80


#15

Thanks. I did know about the reason the Buckingham was developed. I also guessed that the BC incendiary was designed to rupture on impact due to how thin the jacket was.


#16

Hi Falcon !!

You are the only Brit interested by these 303 !!!
Funny, I thought it would interest more British people because 303 is their national ctge and they surely do not know the items I showed.

You are in the military ???
JP


#17

[quote=“jean-pierre”]Hi Falcon !!

You are the only Brit interested by these 303 !!!
Funny, I thought it would interest more British people because 303 is their national ctge and they surely do not know the items I showed.

You are in the military ???
JP[/quote]
No, I am not in the military, I am only 16 years old and at college!


#18

[quote=“Falcon”]
No, I am not in the military, I am only 16 years old and at college![/quote]

16 years old !!
And you know already so much about ctges !!
I am impressed.
It is good to see some young people are studing this field seriously.

JP
PS : Did you put the ctges I gave you on your website ?
If I was you I will carefull compare the rims of some of them (the oldest) to the British ones you already have. (:=


#19

J-P - Reference" You are the only British collector interest in these French .303’s." Jean-Pierre, you have to got to get over this idea that if every single person who is interested in what you post, which I kow for a fact are dozens, do not write in, that no one is interested. Lord, if everyone who liked your postings, including me, write in on every one to say how much we were interested in, it would expand every question on this Forum by eight and ten pages.

Believe me, my friend. Your postings are appreciated and are interesting to many!

John Moss


#20

[quote=“jean-pierre”]
And you know already so much about ctges !!
I am impressed.
It is good to see some young people are studing this field seriously.

JP
PS : Did you put the ctges I gave you on your website ?
If I was you I will carefull compare the rims of some of them (the oldest) to the British ones you already have. (:=[/quote]
I am the only young person I know who is seriously interested in cartridges. It all started when someone gave me five fired 7.62 Blanks (British Made) in 5 M13 links to make a short piece of belt when I was 7 years old. I began to research the 20 or so inert cartridges and cases I had acquired in 2003. I found the IAA site and headstamp guide which I used to identify the makers of all of the rounds I had. I researched more and more, and acquired even more cartridges, first at local flea markets, then antique shops, then the internet and finally contacts I got through the forum.

I have not put your cartridges on my website yet, the last time I updated it was April some time (I think). I have not had time. College is 2 hours away from here, I set off at 6:30am and get home at 7:30pm.