One good thing I've found out. It appears making black,powder here is NOT illegal. One enthusiast, investigated the legalities and making it non commercially is legal.

Test BP screened as home made FFFg in fineness was shot and was very effective. And seemed to be a very usable alternative to commercially purchased BP. Hard to find and source here these days. Tested in a revolver. Snappy good power.

The gentleman made his own charcoal, used saltpetre and sulphur, not sure of the formula, and a small rubber (?) sample tumbler to crush and mix the BP. Kitchen sieves to sort the BP into finished sizes. There might be more to it.

If I ever get a cannon, homemade BP would be essential.