Parts for a mod.100 Extractor, pin and spring problems

Question
I have had 4 new extractors, pins and springs installed. Every one has not lasted thru one firing, Why? I have a certified gun smith scratching his head over this one.

Answer
Not really sure without seeing it. If the extractors are replacemnt parts, they are probably oversize and need to be fitted so they don't get battered.  Also, what are you using for ammo? Are they factory rounds or hot handloads? They could be generating too much gas pressure. The gas cylinder plug usually doesn't need adjustment but perhaps it has been adjusted sometime in the past, or perhaps if it was short-cycling at some point, somebody may have opened up the gas cylinder port as you sometimes need to do with replacement Garand barrels for example. Also you could have your gunsmith retemper the extractor as perhaps they weren't tempered after hardening which would leave them brittle and prone to breakage. Thanks.