Azshooter,
WILSONS RUGERMANIA's site that states:
Quote:
one feature that set the M77 far and above any of the other competition was its one-piece investment cast receiver and bolt. Many tests on the strength of an investment cast bolt were done and it was found that when the bolt finally failed, at about 40,000 p.s.i., only a piece of the bolt lug and its locking surface were broken away. Comparable tests on Mauser & military Springfield bolts sheared their bolt lugs away at only 19,000 to 29, 000 p.s.i.
must have forgotten that the 308 and many other cartridges today routinely generate over 52000 PSI - how is it that two rifles routinely chambered in modern cartridges failed when exposed to half their rated working pressures?
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Dirty Harry,
you are right - with all things being equal - heat treating and alloy the same a forging will always be stronger than the cast
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Lawdog,
Casting whether it is investment or sand makes a product with a random grain pattern while a forging forces the grain into a pattern that strengthens the piece. Investment castings are much better than sand castings due to dimensional tolerances and the smooth finish.
Investment casting has been used in jewelry for years - "lost wax" casting is an example of investment casting (the "investment" is a vacuum formed mixture that holds the lost medium until it is heated)
A quick note here - turbine compressor blades have been sand cast for years.
PaulS