We go round and round with this one...but it never did make sense. I believe it to be a rumor, just a story that I never heard until the internet came forth. The rod would be miniscule and a locking rack would make far more sense in every way. To lock a group of rifles you'd need a rod umpteen feet long, that would be susceptible to bending and then would never fit.
Got pics of this locking system?