Tinker, I don't think that the change from 1/2 ounce to 3/8 ounce is enough to change your powder burn rate sufficiently to require a powder as fast as Unique. Personally, I would stick with the 2400 or 296 until the sound of the report indicates a low pressure situation. Unique is more than one step up in burning rate from the classic 410 powders. Unique isn't going to blow up the gun, but its greater pressure and faster burn rate shouldn't be neccesary for acceptable performance. Try the slightly reduced charges of classic 410 powders before switching.
