Quote Originally Posted by JB101 View Post
For what calibre?
It's never that simple is it. Sheesh.

As a rule (And forgive me if I'm teaching you to suck eggs, not trying to patronise you) the faster burning powders i.e. N110 are better for lighter and smaller bullets then the slower burning powders i.e. N170 to reduce the possibility of overpressure.

The heavier bullets have more inertia and therefore need a slower, longer 'push' than a fiery 'bang' from a fast powder if that makes sense.