Dave, it depends a lot on the load. If the muzzle pressure is too high, it will blow the wads into the shot cloud with disatrus effect, as you found. Without a choke of some kind to slow the wads down, you should to re-try the short gun with softer loads. 2 1/2 drams and 7/8oz to 1oz of shot should do it. Of course, you'll have to juggle wads around. I have a friend with a 10 bore Westley Richards double which does wonderful job on clay birds with 1 1/8oz loads. In his 6 bore double ball and shot gun, he uses only 1 1/2 oz shot. It's just a pop-load in that big gun, but hammers birds, live and clay.