For the .410 use Winchester 296 or its counterpart H110. For all intent an purpose's they are the same powder. I use the Milsurp WC820, but its getting harder to find, an more expensive.
For the 28 I use Longshot. If you're using the old style HS hulls (Not the CF hulls) you'll have problems getting it all in there using Universal, its to bulky. If you're using the new style HS hulls (read longer hulls) you won't have any problems with Universal.
Oh, one other thing. Stick with the Winchester HS hulls. They last longer an reload better than the Remington STS's.
I like the Winchester 296 for the .410 and Unique for the 28g. Surprised Unique had not been mentioned up to this time; it can also be used in the 20 gauge which gets one more powder off the bench. ..............AJ
I've been usig Unique now for 25 years and love it, it can be used also in 12 ga and of course 28 ga. It was great for in since in the beginning i could not afford 2 or 3 powders in order to try to shoot all for guns in my younger E=3 and E 4 days. In the 410 i have been happy with Scots 4100 with was reccommeded to me by an olser shooter who is a great shoot he in Nc by the name of Harold Powell . Steve