Tomster is right. I also own an Optima Pro. I called CVA and the tech guy told me that it will indeedh handle 150 gr of BP or Pyrodex but 100 gr is all you need. More than 100 gr is just a waste.
Mine shoots 245 gr Powerbelts very well with 2 - 50 gr Pyrodex pellets.. The fiber optic sights are excellent and cloverleaf groups can be expected at 50 yds.
One note of caution however. To keep your rifle in top shape. After a shooting session, be sure to take the forearm off, break open the action and remove the barrel from the receiver and wipe it off. Its amazing how much powder build up occurs under the barrel. Its mostly just smoke but it is still corrosive.
It only takes a few more minutes during cleaning.
And be sure to get youself a good quality breech plug grease and apply it to all the treads of the breech plug prior to re-assembly.