[QUOTE=BC38;138564553]Can you elaborate on this? Seems to me increasing pressure would pretty much have to correlate to increasing velocity - and vice versa. How could it not?

Trying to avoid all the linear correlation that has been stated here I will answer this one question only.

Increasing pressure does increase velocity to a point. The problem is when additional powder causes additional pressure without a significant gain in velocity.

Each powder has its own working parameters or the load range where it performs the best.

That is why we use 231 or Bullseye for light target loads. Unique, AA5 or similar powders for medium loads. And 2400,AA#9 or H110 for full power magnum loads.

The slower powders will give the most velocity at safe pressures with some exceptions.

A magnum powder such as Bluedot is wasted in a .38 Special case as are most of the slow burning powders are made for magnum loads.

The light target and medium powders tend to be the best to use in the .38 Special.

To learn more get and read published reload books and articles.

There is a wealth of data and information available besides all the well seasoned reloaders on a public forum.

BLM