I have a late model(1984)S&W M28-3(Highway Patrolman). This gun has not been fired much at all. The cylinder to barrel gap, measures .007". Is this gap OK-or, if too excessive, what is the proceedure that I could follow(If possible?)to shim the cylinder to obtain a cylinder gap of .004" to .006"? Is there any problems with doing this(Either in doing the job itself-or, in the end result of doing this?)? Or, since this gun hasn't been fired much, should I leave this cylinder/barrel gap(.007")just as it is? I can't imagine, that this gun has been shot loose(Since it has hardly been fired at all?)so, it would seem, that S&W just built this M28-3 with this looser, barrel/cylinder gap? Please fully explain and clarify your answers? Thanks.