Which type of powder can cause serious injury if used in a muzzleloader?

Modern smokeless powder can cause serious injury if used in a muzzleloader because it is significantly more powerful and has different combustion characteristics than black powder or pyrodex, both of which are designed for use in muzzleloading firearms. Muzzleloaders are constructed to handle the pressures generated by black powder, which burns more slowly and produces less pressure than smokeless powder.

Using smokeless powder in a muzzleloader can lead to catastrophic failure of the firearm, which could result in injury to the shooter and bystanders. Muzzleloaders are not equipped to handle the rapid combustion and high pressures of smokeless powder, making its use extremely dangerous in that context.

In contrast, black powder and pyrodex are specifically formulated for muzzleloading applications and, when used correctly, are safer for that purpose. Granulated powder is a general term that could refer to powders intended for various applications, but its safety would still depend on the specific type and intended use.