how about we look at the fact that the Federal LE127 00 ALSO penetrated ~20" as tested by Brassfetcher.
First, the LE127 to my knowledge is a general law enforcement load not specifically designed for HD
Which is why the first shells in my HD tube are Remington Ultra Home Defense high density BB loads and the last three are Federal Premium Personal Defense 00 (similar to LE127 but FPS is only 1145 FPS compared to 1325 FPS for the LE127). Then, if the Chinese Red Gaurd attacks along with the Cuban International Zombie Brigade I have an ample supply of slugs - ALL 12 Gauge.
I am amazed that anyone continues to argue the superiority of the .410. Their arguement boils down at best to it will get the job done if accurately delivered. The same is true of the .22 and I suppose of a rock if slung with the skill of David at Goliath. Ask yourself which load is most likely to do the job if delivered with the same degree of accuracy; the 12, 20, or the .410.