Let me add a little fuel and fan the flames of an old fire.
Back in the 1930’s, the Springfield Armory inserted a special notice in the AMERICAN RIFLEMAN magazine. In the notice, it was indicated that when a LN (SHT) M1903 rifle was returned to the Armory to be fitted with a new barrel, it was standard Armory policy to replace both the receiver and the BOLT (at no charge). However it was further indicated that as of that date, because of complaints from patrons, the bolt would no longer be replaced unless the patron requested it.
This would indicate to me that the Armory found it desirable and recommended replacement of LN (SHT) bolts in addition to receivers. I do not remember of reading about many bolt failures; however, I do remember reading that a LN bolt had failed by shearing off the two locking lugs and part of the safety lug. It was being used by a competitive shooter in a match to “slick up” a NS action. Fortunately the broken safety lug wedged the bolt in the receiver so no harm came to the shooter.
To shoot or not to shoot a LN rifle is the choice of the shooter who assumes full responsibility for the results. As has been pointed out many times, reported failure of LN rifles has been relatively small in comparison to the number of LN rifles built. The majority of M1903’s used during WWI were probably LN’s. Few if any failures were reported-whether because they did not fail or the failures were not reported, is undetermined. The USMC never, to the best of my knowledge retired its LN rifles and I have seen correspondence where the USMC issues LN rifles well in to the 1930’s.
When I find the article again I shall post it.
FWIW