I am have problems with my RCBS handheld primer. After seating a primer and after the spring opens up the handle to allow another primer to be seatedt the handle will not go forward. I have taken it apart and everything looks fine but as soon as I put it back together and seat one primer it cannot be squeezed forward. Anyone got a clue as to what could be wrong? Could it simply be worn out? I bought it new approximately 5 years ago and have probably primed somewhere between 3500 and 4000 rounds with it. Also, if I were to replace it what kind would you buy? Thanks in advance for your help.