It's true that there is a point where less powder in a cartridge can cause a detonation that produces a pressure spike that can cause a gun to explode. The type of powder, shape of the volume of the case, and other factors which are too complex to discuss in a simple message on a forum, all affect the the burn rate and pressure curve of the powder in a cartridge. Having little or no experience, and attempting to just wing it, without safe experimentation, can lead to injury and loss of body parts. Please understand that no one on a forum can provide a guarantee that a recipe using X amount of Y powder in a Z shaped cartridge will be SAFE all or even part of the time. My personal experience in reloading is extremely limited to one or two cartridges. When you experiment with cartridge sizes, powders, and loads outside the main stream of what guys typically reload, you're taking a huge risk if you haven't created a means of safely measuring the pressure produced and consistency of the detonation. I'm talking about money spent on a testing rig, fired MANY times with an experimental load under conditions where persons are at a safe distance and protected properly from an explosion. Sounds extreme, but such proof firing was the basis for testing firearms for hundreds of years before standardization of barrel strengths and powder compositions were made. Experimentation requires a careful and well thought out approach.