Unfortunate wording

I finally got round to buying a poppy this year. By this point I've normally lost ten of the blighters.

When I went up to the seller, I realised that I only had tiny bits of change, mainly 2s and 5s and so apologised by saying "Sorry, I've only really got shrapnel at the moment." Only realising a bit too late that this is probably a deeply inappropriate phrase to use really.