I sort of wonder if you can get enough Steel into a 9mm to make it work. I have a bit of an older bulky slow burning powder called AL-8. There is data for it in the 357, 41, and 44 magnums but nothing for the smaller capacity cases. I suspect Alliant Steel will be similar when it comes to the 9mm, 40 S&W, and even 38 Super (The Super in particular since a lot of the usual 38 Super powders have been hard to find locally). 20 grains of steel with a 7/8 oz slug will likely result in a poof load. Most of the steel shot I am loading with Steel generally starts out in the high 30 gr loads for a 1 ounce shot charge. Loading light paylods with very slow powder will generally result in something that does not have enough pressure to burn right. Case in point.. I made up a 6 - 00 buck load with Blue Dot.. I used the data for the 1 1/8 oz load (9 pellets) for the 6 pellet load (3/4 oz). When fired, the pellets barely made it out of the barrel and they were going so slow that I was able to track their path to the berm I was firing at..