I'm going to be doing some rangework with a 20 ga USH in the next couple months.
So likewise, I am curious to hear some of the responses to your post.
I haven't spent a great deal of time with this gun but so far the Platinum Tips (1,700 fps) seem to pattern well.
I'll also be shooting some Hornady's (1,800 fps) and the Federal Barnes Exp (1,900 fps) to see what it likes the best.
Just a suggestion:
But you may want to also post this in the Slug Gun Forum that appears under Shotguns and Wingshooting!