I can concur about the filthiness of Longshot. I've used it in 12 and 20 gauge and it leaves a lot of powder particulate in the barrel.

I find the primary advantage of Longshot is that you can make a 12 gauge 1 1/2 ounce field load in a 2 3/4 hull and that it is generally available for purchase these days.

Otherwise, I agree to investigate alternatives. I'll be looking into 20/28 as well for my 20 gauge needs.

As far as data, the Hodgdon Reloading Data Center can tell you the GD, BD, Longshot, and other powders they make. Nothing on 20/28, even though they distribute it.

Thanks!