Here is some maximum data for jacketed bullets from Alliant, using this under a cast bullet will get you more velocity than is listed:
180gr JFP 7.0gr Unique Fed 200 primer 1125fps 1.58OAL
180gr JFP 9.7gr Blue Dot Fed 200 primer 1260fps 1.58OAL
This load is from an article by John Taffin in Guns several years ago:
180gr LTC 13.0gr H110 1230fps from a 8 3/8" M27.
John
http://www.handloads.com