6.5 CM: 52-53 gr case capacity
6.5 SLR: 55-56 gr
6.5 PRC: 66-67 gr
6.5 SAUM: 70-71 gr

The PRC has 25% more capacity than a creedmoor, and 5-6% less than a SAUM. In quickload, holding pressure constant at 57k psi in a 26" barrel with 140 hybrids, a 6.5 SAUM (H1000) is about 30-40 fps faster than a 6.5 PRC (H1000), and the PRC is 220 fps faster than a 6.5 creedmoor (H4350).