.50", Bakellitefabrikken red coloured blank.

[Bockscar]

Is any other member witnessing the apparent self destruction of their own examples?
Whist doing some house keeping on my collection, it was noted that there were annular lines on my example....closer inspection revealed these to be cracks, and on handling the round it was found that the outer casing had broken into about five larger pieces and lots of smaller fragments.
Closer inspection of the smaller pieces showed that case material is actually crumbling away and has no mechanical strength at all now.
With the outer casing now removed, the inner powder case can be removed easily from the aluminium base and details observed. This inner casing shows no signs of degradation whatsoever and although similar in appearance to the outer casing, I am thinking now that this is of a different composition.



I would be be interested to know if any other collector has seen anything similar with their examples... At this stage I wouldn't say that the problem was due to storage conditions, although this could be maybe be factor, but examination of the remains seems to indicate that the material is unstable and is basically crumbling away to nothing.

Bockscar.

 

[kiwieod]

I have had some similar reactions with some of my 50bmg plastic blanks although not as bad as yours.ive had cracks/splits appear from the aluminum base up towards the front end
I have mine stored in nice dry stable temperature safe and always wonder what caused it
could be powder reacting with plastic/aluminum
also you don't know what happened to the round before you got it

 

[Eggburt1969]

Unless its been cycled from really hot to really cold many times, or been out in the sun, it's likely the diffusion/migration of the propellant's energetic plasticiser into the plastic causing its degradation. It's a known problem with things like the celluloid containers for mortar incremental charges.

 

[switch]

Good Morning all
If I recall correctly, a large quantity of these red coloured plastic blanks were surplus to requirements after the making of the film "Saving Private Ryan". They have an aluminium head, that is unheadstamped, and all examples I have seen exhibit cracking and crumbling to some degree. The actual "charge container" seems to last longer than the rest of the blank, but it will fail eventually. I would speculate, given the volumes of these things available surplus that they had production problems from the start, leading to reject batches becoming available. I am not sure what the propellant actually is, but I would agree with Eggburt1969's suggestion. My examples are certainly getting worse with time, and they have been correctly stored for quite a while.
Cheers
Switch

 

[Bockscar]

Well at least it is now apparent that this problem is not confined to my example alone......
Thanks for your replies on this matter guys, much appreciated.
I don't suppose it would do me much good to look for another example if they are all going to end up like the one I have already!

Bockscar.

 

[kiwieod]

I would look for another one,i have some that are exactly the same round yet one has split the other hasn't!