I have the Rossi .410/.22 youth combo my son and I shot the cheapo Winchester superx 2.5 inch foster slugs at 25 feet, my nine year old son got fist size groups with them we also shot some federal judge loads these were 2.5 inch with 3 OOO buck, at 25 feet it was one big hole the judge loads shot very well out of the short modified choke on the youth barrel, this gun is about 8 years old, so maybe something has changed but never heard you couldnt shoot slugs out of these guns, for us this is a perfect pack gun , when taken apart it fits nicely in common backpacks, in fact I am making a padded insert to hold the pieces so they dont nock around inside, I am going to do further tests with buck and ball loads the .22 barrel shots very good also, would love to hear how the pick 4 performs, I think these combos are a good deal, and the youth .410 combos actually fit youngsters! I will research the no slugs warning, was this in youre owners manuel?
Kaveman