Promo is not a great powder for what you want. It is designed as a full target load at a cheap price. Look at Extra Lite or ClayDot or American Select.
In fact just go to Alliant Powder web site and pick 12 Remington Hull, select shot charge, primer and powder, all, to see your best options. I'd go for a 1 ounce load. The lighter loads tend to have more velocity to get proper powder burning.
Agree with that list of powders. I've used all of them in Gun Club/STS hulls for light (7/8 or 1 oz) reloads at relatively low pressure. Extra Light is probably my favorite, but it's been hard to find of late. Fortunately, I had most of an 8 pounder of American Select, so I decided to use that up and keep my eyes open for Extra Light. About the only negative with AS compared to XL is that it takes a bit more powder (2 or 3 extra grains). Cost is pretty similar, so that makes XL a bit cheaper.
