Does anyone know of a UK supplier for these 5.4mm lead balls for the old Swedish Excellent Gevaret rifles? Or do I need to search Sweden or Germany?

I am (slowly) getting one back into action but now feel I need some ammunition with which to test my endeavours.
I have also heard that the rifles can be quite powerful but I am having difficulty accepting that at present when you consider the charging pump is basically a bicycle pump and, with the recommended 10 or 12 strokes of the pump, the air pressure in the reservoir is not going to be great.
But I may be surprised ...

Cheers, Phil