I was using 90 grains of Pyrodex RS behind a 240 grain Sabot. Accuracy was the same with either a musket cap or a #11; at 100 yards I was shooting 1 1/2" groups. I have tried 90, 100 and 110 grains of pyrodex with the 209 primers and I can't even get anything resembling a group to measure. I am going to try the #11s again today just to make sure it isn't the scope or some other external cause. As muzzle loading season is fast approaching I will likely stick with the #11s and experiment next year.