This refers to the specific propellant charge specifications provided by Ramshot Powders for their TAC powder when used in cartridges chambered for the .223 Remington/5.56x45mm NATO. These specifications typically include minimum and maximum powder charges (measured in grains), corresponding bullet weights, suggested primers, and expected velocities, pressures, and overall cartridge length. An example might include 40 grain V-MAX bullets propelled by a specified range of TAC powder, ignited by a small rifle primer, to achieve a specific velocity within safe pressure limits.
Accurate propellant charges are essential for safe and consistent performance in firearms. Using established load data helps ensure reliable ignition, predictable muzzle velocities, and prevents dangerous pressure spikes that can damage firearms or cause injury. Historically, reloaders have relied on published data from powder manufacturers like Ramshot to achieve optimal results and avoid potentially hazardous experimentation. This data reflects extensive testing and provides a safe and effective starting point for handloading.