Jim
In addition to the info Harold has provided you with, you might consider joining the 16 GA low pressure reloaders group through the 16 Gauge Society
http://www.16ga.com/forum/viewtopic.php?t=921 . Plenty of tested low pressure 16ga loads to choose from. I believe the cost is still $20 to join. The only caveat is that you do not share the information unless it is with other members.
Cheers,
Marcus
__________________
"Nowadays, when one is forced to cross the country in a few hours and drink three-day-old beer, ain't it a pleasure to know, as I'm sure you do, that good friends, good bourbon, and good tobacco are slowly made."
Gene Hill
www.cure.org