You would be surprised at the availability recently, at least here in MN. It's no 12 or 20 gauge, but it's close to .410. You can get both #8 and #6 lead shot almost anywhere, along with #4 steel shot. For whatever reason, people only want 1 ounce or 1 1/8 oz, so no company bothers with anything else. I personally prefer 1 1/4 oz, and can see where a 1 3/8 oz load would come in handy. There are at least 3 brands of slugs, a number of hevishot loads, bismuth loads.