I recall an article in a Gun Digest years ago by Roger Barlow titled, if my memory is anywhere close to correct, Square Shot & little Flying Saucers. He reported on making both homemade cube & disc shot. He did this for the cube shot by pouring a lead sheet & then cutting it into cubes & for the disc shot by placing regular shot between steel plates & pressing them into discs. As best I recall his results proved to be acceptable for a short range spreader load but would be considerable work if more than a very few shells were needed of this type.
Orvis used to sell the flattened, disc shot loads. Really opens up the pattern--but it pretty much ceases to exist beyond about 20 yards. Cubic shot, far as I know, is off the market.
Earlier on, I mentioned modifying the Polywad spreader discs by cutting some half circles around the edge. Jay Menefee uses a similar method, but he cuts holes in the discs. I have never done side by side tests of Mike's method of shot on top of the insert vs modifying the insert, but when I worked with modified inserts, it solved the weak center problem. Easy enough to modify a bunch of inserts while watching TV; saves one reloading step. I also tried one size smaller insert to see what would happen (20ga in 16ga reloads). Thought that might be the easy way. Some improvement of center weakness vs unmodified inserts, but not as good as the modified inserts. I never tried going 2 gauges smaller (20ga insert in 12ga reloads), but that might also have possibilities.
At any rate, spreaders are just the thing if you have a tightly choked gun and don't want to have the chokes opened.
