I bobbed me hammer on my GP-100 and no issues with reliability. Spring pressure is what will make it go bang not hammer mass. If the latter was the case then how do all those semi-autos with skeletonized hammers shoot without issue??? Take a look at the hammers that are available for the S&W 686. Virtually half or better of the hammer has been machined away and they function like a raped ape.
NRA Life Member, NRA Range Safety Officer, NRA Certified Pistol Instructor, IDPA Safety Officer, USPSA NROI Range Officer,
ICORE Range Officer, ICORE Match Director ,MAG 40 Graduate
As you are, I once was, As I am, You will be.