Thanks much for posting that link. The gelatin tests there clearly prove that Birdshot is extremely lethal at close range.
I see absolutely nothing on that website to support your contention. In fact, the photos there conclusively show the birsdshot loads to be highly damaging.
Just look at this gelatin block showing #1 Birdshot ( yes, Birdshot that is between #2 and B in size, and works out to .16 caliber in size:
Penetration in the gelatin block was over 9 inches. The temporary stretch cavity was so huge, that it ripped open the entire gelatin block, as you can see in the above photo. And here is a close-up of the permanent cavity, which is also enormous in size:
A load of smaller #2 Birsdshot also penetrated over 9 inches, and caused this huge wound:
And has been previously pointed out by others, even the lighter 1 1/8 oz load of smaller #4 Birdshot would have been very lethal. Here is another view of that gelatin block, and you can see how badly that block was shattered too:
Again, thanks so much for providing this data that definitely proves your arguments against birdshot to be false.