I still have a few pounds of SR4756 but if I had to go with something else, I would want to preserve the way the loads are lofty enough for me to easily enough see the powder before placing a bullet for seating. I would use the Lee VMD table here and multiply it by the number of grains in powder company data for each load of various powders for your cartridge. Unique and American Select should be among those to check, since their VMDs are close or higher than SR4756's relatively high VMD.

SR4756 doesn't always burn completely, even with magnum primers, so it will be a plus to get away from that minor issue.

5.0 gr of BE-86 with 158 SWC is an accurate load for me in 38 Special, which is where I currently use SR4756 the most. I also use it on light loads of 357 Magnum with 125 gr bullets, lead and jacketed. BE-86 works great there too.