Belgian 47mm APC Round

[Big Dave]

I believe someone will put me right on this one, bought during the summer this FN 47mm AT round .Now is it the ballistic cap or just the cap [ i always thought a APC round had just a blunt cap and a APCBC had a blunt cap and a pointy one ] .this one has a cap that unscrews [see pics] .I thought the BC was usually fixed to the front of the shell ,welded or otherwise? The case is marked FN ,LOT14 ,C47 , and 1937 and the projectile has a Bin a circle and a 3 on the base ,thanks Dave

 

[Chris 42 RQ]

Nice round !

Hi Big Dave in answer to your question I believe that the early A.P.Capped rounds did indeed have a "screwed" on cap much the same as yours !

The reason for this was that in the early days of Munition manufacture it was difficult to "Spin" or "press" sheet metal as the "dies" that were needed to "press" the material were many as it could only be done in stages and these "dies" did not last for many operations due to the quality of the steel available at the time.
Therefore the easy option was to fully machine all projectile components.

Very nice item, and I should think rare too!

Chris :tinysmile_shy_t:

 

[Big Dave]

Belgian 47mm AT round

Hi Chris thanks for the info ,allways thought the APC and APCBC rounds were a wartime development and had never seen one with a screw on cap till i bought this .Thanks again ,Dave

 

[Andre Durieux]

shell 4,7cm belgian penetrating

Hi
Your jugement Chris is all correct.
a other picture of this.
amicalement
Andre

 

[Falcon]

Do these shells have a separate hard core, or is the cap simply to get the best ballistic performance with the ideal shaped penetrator?

 

[Chris 42 RQ]

Hardened cap or not ?

Falcon in answer to your question, the "body" is hardened steel and the nose cap is usually of a much softer steel such as "Mild Steel" as screwing two hardened materials together is not always a good idea as they can end up breaking and/or siezing together, this could happen on firing and potentially might upset the ballistics were the cap to "strip" its thread due to this issue.

Chris :tinysmile_shy_t:

 

[Falcon]

Thanks for the info. If the body is all hardened steel, does this mean that hardened steel comes into contact with the barrel, or does the cap include the boroulet? (not sure if that is the correct spelling).

 

[Chris 42 RQ]

Hardened core versus barrel !

Falcon in answer to your question the Hardened steel core on the smaller calibre rounds tend to have no "Bourelet" and you are right in as much as the hardened steel core will come into contact with the barrel but being so precision made this only creates negligable wear and tear on the rifling.

I do not think I have ever seen a soft "Capped" projectile that has the "cap" act as the "Bourelet" as I suspect that the softer material would actually lead to greater barrel wear were there to be any "out of tolerance" errors on the shot as this would encourage the shot to settle on one side of the barrel causing that side greater stress and therefore greater wear.

Smaller projectiles ie 20mm cal to about 57mm cal (Shot) generally have no "Bourelets" as the items are turned from solid "Bar Stock" and as such are fairly accurate with regards to their "centre of Gravity" but Shells, ie High Explosive are made in a very different manner ie a bar is "Forged" and has its internal "ogive"formed by a series of operations involving great heat and this method can lead to the centre of Gravity not being true to the centre line of the projectile and therefore these "Shells" usually have "Bourelets" machined on the bodies so as to reduce the area that comes into contact with the rifling of the barrel.

Hope that makes sense Falcon.

Chris :tinysmile_shy_t:

 

[pzgr40]

What type of powder was used in these shells? Sticks (? x long?), either strips of powder. What colour are they.
Thanks in advance, regards , DJH