Sugar (fuel) and an oxidizer (I will NOT specify) CAN be a (poor) substitute for gunpowder. If they were quieter, it was because they were driving the bullet a LOT slower, with a lot less energy. If you are planning to get into reloading, please do one of two things- 1. Read the reloading manuals, and follow instructions PRECISELY- that means NO substitutions of bullet weight/type, powder, or primers- OR- 2. Take out a large life insurance policy. I have worked in explosives for over 45 years, and yes, I know of field expedient substitutes for gunpowder. However, those are used only in military circumstances where I am cut off from normal channels of supply. They are sure as heck not used as a matter of convenience or cost. Today I was at the range shooting .357 Mag handloads that are putting out about 700 ft lbs of energy. Carefully developed, used only in one weapon (not the average 357) AND developed from standard loading data. If sugar was a good substitute, I sure as heck would not be spending money buying Bullseye, Blue Dot, and 2400!