any gunwriters or other people with experience. What is the best powder for use in my 30-06 encore pistol 15 in barrel, I probably keep the bullets 150 gr and under. I would like to get as much velocity as possible.so I need a fast burning powder, any advice would be appericated.

If you want as much velocity as possible, use them same powders you would when looking for the most zip in a rifle.
The notion that fast-burning powders produce more velocity in shorter barrels is a myth.

If for some reason you don't believe JB, take a look at Hodgdon's data for 15" barrels using rifle cartridges. There is no significant reordering of powders vs. performance compared to the rifle test barrel data.