A good rule of thumb for TB in almost any caliber is that a full or 95% capacity charge will get you about 60% of the velocity of a factory load with the same weight jacketed bullet. For instance, if a factory 30/30 with a 150 grain bullet is about 2400 fps, then a 95% TB load behind a 150 gr CB will be approximately 1400 fps. In my case, I no longer weigh my TB charges, I do them by volume and I have had little success going below 80% for accuracy. TB is interesting to work with because with all the other powders I use, I use charge weights.