Assuming your Marlin has Microgroove rifling, you are likely to run into issues with cast bullets vis a vis accuracy even if you keep the speed down. Microgroove barrels are not the most tolerant accuracy wise with cast or lead bullets due to a variety of factors. The generally accepted limit to maintain accuracy is 1600 fps; not taking into account bullet to bore fit, specific hardness, etc.
While AA#9 downloads a bit better than H110 / W296, you really want to go to a faster powder especially with those lightweight bullets. AA#9 will leave a fair amount of unburned powder reside when you get too low on pressure; go lower and you will get squib loads.