I just got off the phone with Thompson Center customer service and they said 150 grains of loose powder, with the exception of Blackhorn 209. The rep said " Do not use more than 120 grains of Blackhorn 209 in any of the T/C muzzleloaders, and do not use it at all in the Black Diamond".
Last edited by Michael396; 12-22-2010 at 06:45 AM.