Years ago, almost 40 years in fact, we use to load "spreaders" with nitro cards layered over increments of shot. Two or three 20 ga. cards spaced in the shot column of a 12 ga.. My favorite was two cards, first one about a third up the the second one at two thirds. We loaded on a 600jr, used a trimmed down .45 case to measure shot and layered shot, card, shot, card and shot over the top. I ran out of 20 cards and used 28 cards and the load got tighter or so I thought at the time. The smaller card was surrounded by shot on all sides and seemed to open the pattern up a little less.
We forget what a blessing the internet is to us these days for information, all be it a mixed one at times. In the dark days we had no source of information of "stuff" unless you had some type of book or catalog. You made phone calls or sent for catalogs trying to see what was available. A lot of what we did was by trial and error and not always very safe in hindsight. And many would not share information with others, unlike today and the "I tried this see what you think" attitude many have. It is very refreshing to see such exchange of help and information.
I wish I had it all to do over again. I do it the same way for the most part but would shoot a few less quail. I know that I personally did not cause the demise of old Bob, it was progress that wiped him out. Wild quail are gone in almost all my old hunting spots as homes have replaced roost and cover is gone. Too many retirees and not enough small farms, cut over timber and weeded fields. We use to have the most quail on farms we raised tomatoes on and those with fields in fallow with great big hedge rows. Crops today are row crops that by "law" are required to be plowed under after they are harvested leaving nothing for game to feed on over winter. Efficient farming leave nothing for the fringe feeders so game must go elsewhere or die off.