I have a couple pounds of Unique left over from years back when I used it to load 20g shells. I would like to use this in my 38 spl with 158 rnfp lead. The load data from Alliant is for 4.7 with this bullet. But I will be shooting this in my Marlin 1897 357 rifle. Will this be a safe load in the rifle? Thanks...Marty