What's new
British Ordnance Collectors Network

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

What cartridge fits this SAP projectile ?

D

DBenz

Member
Hi,
Trying to find a cartridges to fit this projectile for a friend, in fact need a pair as he has two of these to display. Had been advised to look for the 2pdr cases but having acquired them after few years of searching, the projectile pair dont fit ! :sad: Projectile being too big. Measuring the case such would fit if we saw it off 4 inches down from the end, as the walls are 1.27mm thick, though brass cases are thinner at the ends for crimping purposes.
Just what is this projectile, usage etc ?
What purpose does the pot on the end serve ?
We need to find a source of two cartridges, any help welcome.


click on pics for enlarged view.
_MG_07_8710 sizes.jpg_MG_07_8714.jpg_MG_07_8715.jpg_MG_07_8721.jpg_MG_07_8726.jpg_MG_07_8724.jpg_MG_07_8725.jpg
DBenz
 
Last edited:
The bottom is marked SMK and 43, so presumably it is off a different round to the projectile it is currently fitted to . It also looks dented so could be a thin sheet steel cup that the projectile has been fitted into, a sort of trench art piece, as its dated may 45 it could be a souvenir from a factory? See if it will come off with a little gentle persuasion....
Cheers
Gary
 
Something doesn't look right with the base of this projectile - the fact that the base diameter is 41.5 mm compare to to the mid-point diameter of 39.75 (40mm) - curious to see what the driving band diameter is?

Could be a factory reject where the base pot wasn't completed???

I'm not surprise that it won't fit a 2pdr or even a bofors case.
 
Could it be an 'S' gun projectile?.I agree with Hangarman,that base pot doesn't look right on the projectile,possibly projectile just 'stuffed' into it because it fitted.Almost looks like a cap for a 2" mortar.
 
Smoke Box

I agree Tim. The container was I believe usually filled Red Phosphorus rather than White Phos. I chased high and low to ID the one in the reference that you give and managed it in the end but concluded that the Navy could have made it easier by having more comprehensive and accessible technical manuals.


NOD6123 Box Smoke HE Shell 3-75oz.jpg
 
This was a QF fixed round because the stampings are on the side above the driving band, therefore the bottom bit is an addition.
From the diameter it may be a 40mm HV SAP .
It looks as though the N in the base stampings is not part of the maker's mark, which would appear to indicate that it is some sort of naval item.
In the normal course of events the Navy does not have a need for smoke boxes in projectiles, either you hit it, in which case there is a visible sign on the target, or it missed and went to Davy Jones's Locker, without visible trace.
It would appear to be from some kind of smoke bomb, mortar or other projectile.
The military had a lot of shell with Red Phosphorous smoke boxes and never used White Phosphorous. I would not like to have been the one removing a plug to fit a fuze if WP was used.
 
Last edited:
Norman,

The pellet appears to be composition "S.R. 388" of which I can find no trace in any document, including MEOS, can you shed any light on it?. It also appears to be tubular, so unless the powder was very heavily pressed I think it would be difficult to get 106 grammes of red phos' in it.

TimG
 
TimG said:
Norman,

The pellet appears to be composition "S.R. 388" of which I can find no trace in any document, including MEOS, can you shed any light on it?. It also appears to be tubular, so unless the powder was very heavily pressed I think it would be difficult to get 106 grammes of red phos' in it.

TimG
Click to expand...

Tim,

The pellet is only about 70 g the rest of the 3.75 oz being made up by the container (presumably). As you know it would need to be strongly stemmed or pressed to avoid any embarrassment when it is subject to the G force of discharge, particularly if it is Red Phos.

I have a good Indian Ammunition pamphlet that gives the ingredients of the SR compositions but of course it doesn't include SR388!
 
SR 388 does not appear in EHDS sheets, JSP 316, Def Stan 08-10 or Cacketts.
Because a drawing was produced, how sure are we that this was ever made?
All the red phos smoke boxes I ever replaced were bakelite.
 
Last edited:
Norman,

No mention in Service Textbook of Explosives 1938 or 1954 or JSP333.

Having done a bit of reading, the Navy make no mention of red phosphorous, but they do make mention of using Fumyl. Notwithstanding that Fumyl is an explosive, is it possible that it was assigned an S.R. number when it was to be used solely as a smoke box filler?

TimG
 
AE501 said:
SR 388 does not appear in EHDS sheets, JSP 316, Def Stan 08-10 or Cacketts.
Because a drawing was produced, how sure are we that this was ever made?
All the red phos smoke boxes I ever replaced were bakelite.
Click to expand...

Bill,

A metal smoke box was recovered from sea bed, but it was a different size.
The use of smoke boxes is mentioned in the Admiralty Handbook on Ammunition 1935 [Page 85, Para 607] and the 1945 edition [Page 42, Para 290] but the filling is not specifically stated.

Tim & Bill,

The use of Fumyl is alluded to (1945 Para 99) and it makes sense because it adds to the explosive effect and produces smoke. A Burster, Pellet, Fumyl was available (used in a 4.2 mortar practice bomb. I believe there were a dozen or so recipies for Fumyl and they were coded Fumyl 1 through Fumyl 12 say, It is possible that they had SR or PN numbers also.
 
excuse me asking, SAP shell, why a flat tip, would have thought pointed would have been better, less chance of bouncing off and more penetration when going in. looks more like a 2pr practice.
 
Hi,
If we are able to remove the smoke pot base, as you conclude, its not part of the original item, what shell case should we now seek, or would those shown be suitable ?
As mentioned there is a pair of these heads with those bases, so maybe trench art for the mantlepiece ? A friend drilled a hole in the side of each and emptied out the stuff that we could hear rattling inside, a dk brown sort of cordite 'strings' came out. He likened it to the 2inch strings in a .303 round. As such would those end 'pots' have a sealed top, I cant imagine they were pushed onto the shell with combustible content visible.

DBenz
 
It is SAP because it is marked S.A.P. and looks like Mk 1/1. There is a 40mm SAP Mk 1 described as : SAP Shot 1, DD/L 11025, Steel. Truncated nose and recessed base.
The other three later SAP marks were fitted for a tracer and one at least, had a pointed nose so perhaps someone thought as you.
(see User Handbook Anti Aircraft Ammunition 1949, P 70). You can even try to get the matching cartridge case on P 66.
I do not have the Maker's mark in my lists.
 
Yes, very strange. this is more like 1s like late 1800's practice, It is the first truncated pointed projectile I have seen since those times.
 
Last edited:
B.T.H. Co.

The British Thompson-Houston Co., Ltd.
Manufacturing electrical engineers
Head Office: Rugby
TN 2121

TimG
 
You must log in or register to reply here.
Top