I have tried indexing several times when I competed with a falling block rifle and could never find accuracy improvement. I have never read anything persuasive that showed that indexing improved accuracy. However, some pretty knowledgeable shooters use this technique so I would like to run an experiment.
Indexing swaged bullets that are near perfect seems unlikely to improve accuracy. However, at present, I am not swaging my bullets and am shooting them in factory chambers and It seems theoretically more promising that indexing might help for these less than perfect bullets and chambers or when neck thickness varies.
Indexing the bullet before the bolt starts chambering it is easy. Knowing that it stays indexed after the bolt is closed and rotated to lock is isn't so certain. The cartridge might be roading different amounts with each shot which would destroy the experiment. I am not sure the experiment is worth doing without having some technique for assuring that the cartridge is still oriented the same for each shot. Has anyone developed a method for indexing with certainty in a bolt action?