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Hardness of chrome moly question

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24 December 2003, 10:14
muzzle
Hardness of chrome moly question
I have heard that chrome molly barrels are harder to flute than stainless. Is this true and for what reason?
24 December 2003, 10:18
Chuck Nelson
As I understand it Chrome moly barrels are harder than stainless barrels.
24 December 2003, 10:29
triggerguard1
416 is the stainless used for barrels, as 4140 and some other close steels are used for the chromoloy barrels. 416 is by far better to machine than 4140. I've heard that 416 has a tendency to gaul when it's being rifled, but this is something that I've never had a problem with on any other type of machining of the material. In fact, we run a lot of 416 for machined parts and I'm able to run my Surface Feet up to as much as 800SFM, as opposed to 4140 at about 450 or less. Where is some of the machining operations we perform, we can mill the 416 at 140 inches per minute, we're only getting about 45-50 IPM with 4140. It is significantly easier on tooling than 4140.