Originally Posted by
lysander
1) The first bolt made from 9310 I know of was made sometime around 1964.
2) There were? I never heard of wide spread problems.
3) And, some say the opposite. Everybody has an opinion.
4) This is more of a statement than a question.
5) Why should NSWC Crane want to test bolts?
6) They aren't "MIL-SPEC" for the M16/M4.
7) Bolts made from 9310 have been used on M60s and M249 for many decades without any issue. According to a 1962 report by Watertown Arsenal, 9310 steel was not only more tolerant of heat treating condition variations than the then 'standard' 8620 steel, it was superior in strength. For these reasons the 9300 series steels have been very popular in weapons breech bolts.