I didn't read the article, but have read PO Ackley's books, and this is nothing new. he experimented with twist rates extensively, and claimed that the RPM is more important that muzzle energy when penetrating. In one test he shot 1/2 " armour plate with a 30.06, 270, and 220 swift. The Swift was the only round to penetrate even though the muzzle energy was considerably less.
The theory is sound, but the question is what do you need to penetrate with a hand gun?
Tread light and carry a Glock 20