3" mortar augmenting cartridges.

[cherryturbox]

Hi, I want to reproduce the augmenting cartridges for the three inch mortar tail fins. I've seen pics of the war time one which look like a plastic tube which has perhaps yellowed with age. Were they clear plastic originally with an explosive in fill?. Also the thread for the the fuze is it BSP or something similar?, also looking for some stencil sets for marking them up. If anyone has an original augmenting tube they could post some pics of that would be a great help.

thanks.

 

[kiwieod]

heres a couple of nice original ones ive had for years.the diameter is 19mm/,3/4''.thin plastic tube.
filling is nitrocellulose.
label on end
L1931
3IN. MOR.
100 GRS N.C.(Y)
LOT DK 69
FILLED M.E
8/42

N.C.(Y) developed from the sporting gun propellant EC3.quick burning and burns regularly at low pressures.hence used for augmenting charges for 3IN mortars.normally in the form of small rounded grains coloured orange with aurine.if aurine is not available dyeing may be omitted.from textbook of ammunition 1942.

 

[millsbomber]

Looking at those pics you could use silica gel as the filler

 

[BMG50]

You also need the springs that wrap around the holes in the tail fin that holds the charge to the tail.

 

[cherryturbox]

Hi, Thanks for your he;p, anyone got pics of the Mk2 capsules ?

cheers

 

[BMG50]

I belive the new rounds fresh from the tube had a cloth bag around the fins that was removed before firing.

 

[AE501]

The bag was of rubberised cotton with a drawcord. Apart from protection, it contained the propellant from any broken cartridges.

 

[millsbomber]

I think the springs can be made from net curtain cord

 

[spotter]

Some drawings of mk1 & mk2 in this old topic..
http://www.bocn.co.uk/vbforum/threa...gmenting-charge-Question?highlight=Augmenting
Also if i remember correctly early 3inch mortars also used rubber bands to hold the augmenting charge in place later replaced with the springs

 

[AE501]

Here are some insights from 1942, 1953/55 and 1963.
There was a comment in Spotters link that the aug cart closing cap was on the inside. Some were and some weren't.
The lengths of the aug cart retaining springs are given.
Dave mentioned that curtain cord wire springs could be used, but only if you made the cartridges of a very strong material (a block of wood?). The real springs are very stretchy but the wire coil is very fine to maintain the balance between keeping the carts in place and squashing them. I would say they are about a quarter of an inch in diameter.
The same principle as the shirt sleeve shortening spring applies. To stop yards of cuff showing, but without cutting off your arm circulation.
In the early pamphlet it mentions that the waterproof bag contained a canister. This was actually a flat plate with a rim about half an inch up or more into which the tail unit sat.
I have included the drill aug cart info so that if using a short range setup, the carts are put in the right place
I obtained the 1955 pamphlet some years ago, having long left the army and found that I had done the the last two amendments.

 

[cherryturbox]

many thanks your help

 

[M8owner]

Here is an image of the bag that protects the charges, and I added a link to a post of mine from a few years ago on a drill round.

http://www.bocn.co.uk/vbforum/threads/90321-British-1941-Dated-3-Inch-Mortar-Training-Round?