There is a lot of information on 37mm on the net. When we find documents that you might find interesting we will make them available here for free download. Note that if you put this in your shopping basket you don't really receive anything, you have to do the download, below.
Lots of recipes --- Free. These are firework recipes that are easily adapted to 37mm!
Here are recipes for various irritants like MACE.
This PDF shows volumes in CCs and Cubic Inches and the grain equivalents for various brands of Black Powder and substitutes (like Pyrodex). Remember that BP and substitutes are measured by VOLUME not weight.
This PDF gives rough grains of water that different ammo cases will deliver.
The following two downloads are about the substances that you can use to make fireworks/payloads. Definitely worth checking out.