Is it really Bows or Guns??

[Timelord]

You should be able to find what you need with a little research. It is even available on ebay come to that! There are alternative substances that can be pressed into service. Just a little reading up is needed - like most things. This is no arcane art anymore - it is all old hat now. An explosives licence is needed to store "black powder but you can make up small quantities for experimentation and immediate use without needing a licence. Pyrodex & other substitutes do not require a licence and so therefore neither will similar home made experimental propellents as long as they do not result in certain substances/classes of explosives. Other than black powder and associated equivalents, a propellent does not classify as an explosive. Not that they can't be swapped around, but the two are different classes of substances and so different laws apply (or not apply as may be the case)
I am glad you with your bow & us with our boom sticks, are not breaking any laws. Regards, TL.