Muddy,
If your .410 doesn't shoot slugs well you can always try buckshot, too.
The come in either 2 1/2" 000 buck (3 pellets) or 3" 000 buck (5 pellets).
My daughters .410 didn't pattern the 3" at all (off the paper) but the 2 1/2" shells patterned near perfect at 25 yards.