Thanks, Dingel and Miller. After waving several Pedersolis about for a while, I believe I will get the choked 20 that Dixie sells. They are on sale now and are choked C/IC, which will probably work for me and allow experiments with ball. If I really like the 20, I'll probably get a bigger gun later. It felt better to me than the 12, tho. The 10 is too much to lug over hill and dale--fine in a blind or a flat cornfield. But not the Coast Range or Snake River Breaks.
Points taken about improvising wadding--I won't. Tempting because I'm a cheap bastard but I don't want to set any of my buddies or their dogs on fire, let alone SoCal.