Here’s an explanation from the AR15.com, Best Choices for Self Defense Ammo:
“Number 1 buck is the smallest diameter shot that reliably and consistently penetrates more than 12 inches of standard ordnance gelatin when fired at typical shotgun engagement distances. A standard 2 ¾-inch 12 gauge shotshell contains 15 pellets of #1 buck. The total combined cross sectional area of the 15 pellets is .964 square inches. Compared to the total combined cross sectional area of the nine pellets in a standard #00 (double-aught) buck shotshell (0.77 square inches), the # 1 buck shotshell has the capacity to produce over 20 percent more potentially effective wound trauma.
In all shotshell loads, number 1 buckshot produces more potentially effective wound trauma than either #00 or #000 buck. In addition, number 1 buck is less likely to over-penetrate and exit an attacker's body.”
I explained all of this to Hal, and he totally agreed with me. He was very knowledgeable about the whole issue.
I asked him, “Then why don’t you load #1 buck into the Flight Control Wad and make a great round?”
He said, “Because we have no market for #1 buckshot loads. The military and police departments request 00 buckshot. No one asks for #1 buck.”
I told him that no one was buying it because no one made it, and he explained that no one made it because no one asked for it. Kind of a vicious cycle.
I told him that lots of people wanted such a load and that if they made it, it would sell well. He said they would consider it.
I saw him the next year, and he remembered me and when I asked him how the #1 buckshot project was going, he said they were looking into it and might just make such a load.
This year at the show, he told me they were definitely going to make the load. My good buddy Zhukov and I also spoke with him at the LaRue Range Day and Hal said it would be on the market in a couple of months and that he would send me some of the ammo to do some tests.
This week I got the ammo. Boy, was I excited. I will not do penetration tests, as they have already been done and the #1 buckshot makes the FBI minimum penetration standards.
But I wanted to test the patterning of this load against non-Flight Control ammo.