Here you go. Reported pressures for some loads at the bottom
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview

The short version is under "Shotshells and Shooting" here
http://lcsca.clubexpress.com/content.aspx?page_id=274&club_id=43784&sl=827060842