What is the source of your load data? Is it simulated or do you test your loads and measure pressure and velocity?

The majority of our load data is derived from simulation utilizing advanced powder models and cloud computing technology. The input parameters include detailed information regarding 

• cartridge specifications: cartridge overall length (C.O.L.), case length, case capacity, diameter, maximum allowable pressure, and related factors;
• bullet specifications: length, shape, boat tail dimensions, material composition, friction coefficient, initial pressure, among others;
• powder characteristics: density, bulk density, heat of explosion, burn rate, etc.;
• barrel length.

The primary outputs generated include maximum pressure, muzzle velocity, and powder conversion efficiency. 

Employing simulation models enables the provision of over 5 million load data points encompassing more than 4,200 bullet types, over 400 calibers, and in excess of 230 powder varieties. It would be impractical to physically generate and test all these combinations. Additionally, other sources of load data (e.g., Hornady) also partially rely on simulated data.

We continuously calibrate our models using empirical testing and measurements. This process is ongoing and incorporates data from the German Testing and Research Institute for Hunting and Sporting Weapons (DEVA).

We also offer community loads, i.e. actual loads that our community members share on xxlreloading.com. IMPORTANT: We do not validate these loads! You are using this data at your own risk.