I am by all means not an expert, but have read that a babbitt bar is like a round or triangular lead alloy rod that it used by a skilled S&W gunsmith to straighten a front sight blade, extractor rod or an overtorqued frame. This gunsmith needs to know how much energy to use and where to exactly apply the striking force to accomplish this. The lead alloy of the rod is supposidly not to cause damage to the finish of the revolver. This sounds way old school and definately out of my league.