have been an avid shooter for 27 years now,spent some time in private security. Just bought my first HK45, this is my first polymere pistol, I know the reputation this pistol has for reliability but was suprised when I fieldstripped the pistol to find only four steel rails, are these rails replaceable if need be? And found fieldstripping and reassembly of this pistol to be a little difficult copared to my other pistols, also not sure i put it back together correctly, does the recoil guide rod is it supose to fit or interlock with the barrel?