Over the last 20 years the natural gas industry has funded multiple precombustion chamber (PCC) studies primarily through the PRCI Compressor and Pump Station Technical Committee but also through other natural gas industry affiliated organizations such as (formerly) the Gas Research Institute. These studies are summarized and compiled in this report aimed at forming a foundation from which to develop new prechamber technology to operate large bore natural gas engines at 0.2 g/bhp-hr or lower.