In Reply to: Yes and Maybe posted by John Marks on February 8, 2001 at 18:34:21:
Crogenic tempering has been used in rifle barrels in the attempt to increase machinability, accuracy, and barrel life (competitive life can be less than 2,000 rounds). While there have been many testimonials, the evidence is still somewhat anecdotal I think. In one controlled test for accuracy, there was no improvement using a treated barrel. But this was done by a commercial manufacturer of "match grade" bullets; those of us who shoot benchrest feel these bullets aren't quite up to a definitive test.The same manufacturer (Sierra bullets) also tested cryogenically tempered bullets -- copper jackets & lead cores. That test showed no improvement in accuracy, & I believe their in-plant physicist predicted no improvement with copper & lead. There hasn't even been any anecdotal evidence that crogenic tempering of bullets helps them hold together better under the heat & stress of firing -- a different application. I know.
As far as machineability of 416-R steel, while many machinists feel it machines better after cryogenic tempering, others do not. A difference in lathe technique: in feed, RPM, cutting oils, reamer steels etc, I would imagine.
In short, unless there is a prediction that the process would help in this application, I'd be wary of testimonials.
FWIW
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Follow Ups
- Re: Yes and Maybe - Charles E 02/8/0121:37:36 02/8/01 (0)