I use 8.3g N320 with a 240g LSWC in my .44 Marlin and that's the best load I've found with it.
I've tried various loads for my .44 as I have this powder for my .357 so thought it may do for both calibres but to be honest I've never been impressed with it in the .44 Best powder and load I've found for the Marlin .44 is same 240g LSWC with 7.1g Bullseye, Its amazingly accurate !
ALL LOAD DATA USED AT YOUR OWN RISK