It is probably one of the 1000 fps models, not the RR 350 fps. But I recall at leasst one in the Denver area where the BB went into the back of-- the head/neck and was fatal.
Guns is guns. I have tried the penetration thing on phone books with a .22--went through one of the regional thin ones. A .25 went in 2 inches, keyholed. Don't confuse fatal wounds with stopping/disabling wounds.