In the last three years, 61 deadly weapons that had fallen into criminal hands have been seized in Greater Manchester. The Turkish-made blank firing handguns had been converted to discharge live rounds.
At least 16 shootings involved the firearms - including an attempted murder. The process is relatively easy and they cost a few hundred pounds.
But once altered to fire bullets, the guns can fetch thousands. From March, they will be outlawed in the UK. Anyone found in possession of one of the weapons could face up to 10 years in prison.
A national amnesty will begin next week. Four specific types of top venting blank firers (TVBFs) will be illegal from the end of next month.
Read more on manchestereveningnews.co.uk