The other day I was in my CCWP class, and my instructor (he's a sherrifs deputy) stated that a hollow point personal defense round, I.E. Winchester Ranger T series, or PDX-1 etc. etc. Expands as soon as it is 18 inches clear of the barrel, even without contacting any BG's. In essence what he was trying to say was that air pressure against the hollow point was enough to cause expansion, and frankly at this point I have to call BS. I dont believe it. Am I wrong??