So here are a couple of examples of 152mm Dummy/Training rounds with different designs of dummy training simulated combustible cases. The blue sectioned projectile is actually a practice projectile to simulate the black HEAT projectile. The blue projectile is sectioned to show the internal hidden PD fuze and TNT spotter charge. This is the XM411E2 projectile. Only the E2 model had the internal High Explosive spotter charge. The danger with this, is that it looks exactly like the other M411 practice projectiles. The only way to tell the difference is to X-ray it, or read the stamping on the side of the projectile. This is one example of a blue painted practice round with a high explosive payload.
This particular training aid is built with a dummy cartridge case made from wood and filled with inert simulated powder grains. The cartridge cases on 152mm Gun ammo were combustible, leaving only the attachment metal nut on the back of the projectile that held the case in place.
The second round shows the method that the normal combustible case used for attachment. The cartridge case shoulder was attached to the base of the projectile with a nut. This same nut is used on the sectioned round, but it is attached to the wood with screws. In a real service round, the nut would pinch the case to the projo base as can be seen with the cardboard shoulder held in place. The case shoulder is then glued to the rest of the case, which is filled with a powder bag full of propellant. In this case, a cardboard container filled with a powder bag filled with simulated propellant. The complete round shows the projectile with attached case shoulder resting on top of the rest of the cardboard case. The shoulder never was glued to the rest of the case.
If I were going to make a dummy case, I think a good laminated wood cylinder cut to the proper profile would work, with an attached nut at the top too screw onto the projectile boss.
Those are some excellant photos and just the information I was seeking.
I have read descriptions about case attachment, etc, but as they say, a picture is worth a thousand words.
It appears the case sides have a taper, as shown in photos #1, #2, & #16. It is almost as if the "shoulder" at the top of the case and the rim at the bottom have the same outside diameter. The inside of the rim to the "shoulder" create the taper. Is this correct? If so, no wonder I could not quite get my head wrapped around how the thing was supposed to look.
Wonderful photo of the ring/nut screwed to the wood case in photo #4. That ring should be quite a challenge on my metal lathe.
With reference to the comment about making the case from a laminated wood cylinder, yes, been there done that - on an M865 TPCSDS-T 120mm Cartridge. There is another thread on another forum that shows this. Anybody want a link (can I do that here)? I used pine on my 120mm case. It looks like photo #15 shows maple. I will have to see what is in the lumber rack.
Please understand I am not trying to make a case with measurements accurate enough to fit into a chamber. I should be able to get measurements from the photos. In this particular "case" (pun intended), close enough will be good enough. I have a projectile. I don't have a case for obvious reasons. I wanted to make something that would show the overall size of the round for static displays that I do from time-to-time. On the other thread I mentioned, we even talked about painting the case or leaving it natural wood. The consensus was to leave it bare wood to mimic the oak training rounds from WWII. In reprospect, perhaps I should have made the case from oak instead of pine. I might do that with this one.
Thanks for your help, gentlemen. I will post photos, when done, but be forewarned that might not be soon. It seems retired life is much busier than "working" life.
