I have posted a new article on my website to add to my series on collecting cannon cartridges, here: An introduction to collecting 30 mm cannon ammunition The photo below shows the five different 30mm WW2 aircraft rounds which got into action:
Excellent work as usual, Tony. I find the German 3cm ammunition endlessly fascinating and so do others, judging from the steadily-increasing prices of inert rounds.....
I'm not too much into these. They are nice to collect when inert, but it's incredible how many people including dealers at flee markets sell dangerous rounds that could still explode at anytime. Unless I'm absolutely certain I don't to even close to these things.
The rules in the UK are very strict and as always, it's best to buy from reputable, established dealers. With the base drilled, and a 'rattle' inserted, they should be safe enough. But yes, flea-markets or militaria bourses on the Continent should be treated with caution, especially the Ardennes area of Belgium where you could start WWIII if you were so inclined.....
It is a great collection though. I believe UE rules are the same now for collection weapons. You can now demilitarize weapons in any of the country that has signed the convention. Before that you could only do it in your own country. import-export is also strictly regulated
I even treat de-acts with respect and never 'tinker' with them. I am always mindful of the British historian (Pimlott, I think ? ) who brought a 2cm shell back from a battlefield, and it killed him when he attempted to dismantle the fuze with a screwdriver.