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2-pdr HE tracer (No.7 or No.10) question

Brennan

Active Member
Does anyone have any basic information on the No.7 or 10 tracer/igniter? Filling, burn time/colour, ect.

Thanks
 
Brennan,

Both are Tracer/Igniters, mean time to self destruction 6.25 seconds, colour of trace - red. Tracer composition is SR 372 AB

The real difference between the two is their method of ignition.

In the case of the No. 7, the body contains an anvil and cap. On firing the cap 'sets back' on the anvil, detonating the cap filling which ignites the tracer compsition

In the case of the No. 10, the flash from the propellant charge ignites the tracer composition.

(Notes on British Land Service Tracers 1961)

Regards

TimG.
 
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Very nice TimG, thank you very much.

One last quick one, do you have the scoop on the No.13?

Thanks.
 
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Brennan,

Alas, no. It was obsolete by 1961 and the only information that I have is that is was a tracer as opposed to a tracer/igniter. I might have something elsewhere with details.

Regards

TimG.
 
Tracer No.13

Hi, this attached to the H.E. proj. to DD(L)16673. as used in 77mm/17Pdr. gun. Also used in 6Pdr.7cwt. H.E. to DD(L)14697. lf unable to get trace data from other members then l will try and dig it out - am in a bit of a mess with tracer documents at present, sorry.Regards, Ron.
 
Brennan,

The 7 & 10 were internal tracer/igniters in so much as they screwed into a cavity in the base of the shell. The 13 was an external tracer that screwed onto the base of the shell.

Similar to the No. 6 in this picture http://www.bocn.co.uk/vbforum/showpost.php?p=22163&postcount=11

There's a very poor diagram in the owner's handbook for the Comet tank.

Regards

TimG
 
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Tracer No.13

Hi, just a quick note: This tracer Introduction for 6Pdr. 10Cwt. External, it is similar to Tracer Shell No.1, closed by brass cap into which is sweated a thin brass disc. Filled with Comp.S.R.372. Priming Comp.S.R.399. Trace for 6.5 secs. colour-Red. Hope his helps, RonB.
 
Tracer No 13

Herewith a diagram which I hope is of use.
 

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Great stuff guys thanks.

Interesting that the 6pdr HE uses it too. Does anyone know if the 6pdr AP/T rounds used an integral tracer or was one fitted?
 
AP/Tracer shot.

Great stuff guys thanks.

Interesting that the 6pdr HE uses it too. Does anyone know if the 6pdr AP/T rounds used an integral tracer or was one fitted?
Hi, My 6Pdr.6Cwt. & 6Pdr.7Cwt. AP/T projectiles have internal cavity bored into base for the accommodating of tracer compo. Cheers, RonB.
 
Tracer, shell, No.13

The No.13 tracer, of steel, is cylindrical in shape and is bored internally to receive tracer compostion. The contents consist of two equal-sized pellets each of 17 grains of S.R.372 tracer compostion, making four pellets in all. On top of these pellets are pressed 12 grains of S.R.399 priming compostion.
Externally the upper end of the body is screw-threaded to screw into the recess prepared for it in the base plug of the shell, where it is retained by a set screw. The lower end of the body is screw-threaded externally to receive a metal closing cap.This cap is provided with two tommy holes, diametrically opposite, for insertion and removal of the cap, and a central hole through which the ignited gases from the tracer compostion can escape.
The central hole in the cap is closed by a thin brass disc, sweated into postion, and is for the purpose of excluding moisture. On firing, the disc is fractured by the propellant charge thus exposing the tracer compostion which is ignited.

Source: Handbook for the Ordnance, Q.F. 6-PR 7-CWT., Marks II and IV. 1943

The 6-PR 7-CWT AP projectiles were fitted with an internal tracer.
 
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I assume the integral follows the common theme in british shot?

.37 inch dia cavity and 85 grains of either SR261/SR372A?
 
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