I don't know that much about it either other than it was a family members gun who is a retired FBI agent. It came in the factory box marked FBI Academy and the other side says used gun S&W. Also came with the 4 sets of grips 17 magazines 20 magazine replacement springs. 6 boxes of federal 10c classic rounds one box of Winchester Western sample c marked for law enforcement only and one box of federal xm100A. I was told the box marked Winchester Western sample c is super rare and very few were ever made trying to develop a load for the gun.