But I believe from experience the following negates the results of this test.
All of these shots were taken from a known distance and angle into bare Ordinance Gelatin in a controlled environment. This does not take into consideration the effects clothing, weather, range, temperature, cover, or body structure.”
I watched a friend get shot in the butt while wearing heavy insulated coveralls, like Carhartt, tough outer material.
The bird shot that was being used tore up the outer fabric layer but not a single pellet broke the skin.
After the shootee got off the ground (he was leaning over to tie a bootlace) he beat the crap out of the novice kid walking with his finger on the trigger.
In light birdshot, clothing makes a big difference. The Box O’ Truth Web site uses denim cloth in their penetration test.
I tend to look at it the other way around...it clarifies exactly what happens if your friend was bent over mooning someone...2 inches of penetration give or take with #8 birdshot. That is on bare skin.
I love the BoT site, but have always questioned tests with a layer or two of denim as being a really good representation of clothing. Of course all tests are really an approximation...even the gelatin. With Denim tests, first they almost always put it directly against the medium (not hanging loosely 1/2 inch in front, they rarely test with other materials like a down jacket or insulated coveralls etc.
Using the bare gelatin tests, with over penetration dry wall tests, the BoT tests etc, for me the absolute smallest I would go is #4 birdshot (.13 diameter shot) with a preference for the next size up that is readily available, #4 buckshot (.24 diameter). If I could find it, I think BB or T (.18 - .20) is probably the best home defense indoor (10-15 foot range) shot. It will penetrate clothing sufficiently and a miss does not go through too many walls. I would have first two rounds of T followed by two rounds of #1 buckshot (.30) with the theory that if I am still shooting after two rounds I am no longer as concerned about penetration and my initial adrenaline rush/nerves will have quieted somewhat and scenario will either be point-blank range or in a defensive position/posture hopefully with time to consider what is behind the target and well aimed shots.