Gun enthusiasts who are interested in finding accurate powder estimates for loading ammunition can find reloading powder charts online from providers of gunpowder, such as Hodgdon, IMR or Alliant powders. Guides offer specifications for pistols, rifles and shotguns.
Users of the online resources are asked to enter a cartridge size, a bullets weight and the specific type of powder used, and its manufacturer. Different powders have different ratios for reloading and each powder maker has developed its own equation for maximum and minimum loads.
The makers of each gunpowder also have resources for those interested in learning the basics of reloading and safety precautions as outlined by the NRA.