In spite of the name, this cartridge is actually a German design from the early 1900s, where it was referred to as the 12.7 X 70 Schuler. It is similar to the 505 Gibbs but uses a 0.510″ bullet, rather than a 0.505″ as does the Gibbs. While this brass is not Bertram headstamped it is made in the Bertram factory to the same specifications.  This brass is packaged in lots of 20. Shipping weight is 450 g/20 cases.