BAT - galling

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PPP MMM

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According to the BAT material specifications the reciver is made of PH 17-4 stainless and precipitation hardened to 36-38HRC, the bolt is made of 4140 chrome/moly hardened to 45HRC.
My question is, how is the PH 17-4 SS resistant to galling especially in the lower (36HRC) hardness with the large head calibres generating over 60 000psi?

Shoot well
Peter
 
galling

Galling will occur much quicker when two steels have the same or very similar hardness.
As a "GENERAL" rule of thumb, it is wise to have two close fitting parts at least 8 points different on the Rockwell C scale---preferably 10 points difference.
Other things come into play too--such as fit,finish and the atmosphere the parts will be used in.
Used for it's intended purpose, I'm sure galling is not a problem with a BAT action--it's a benchrest action and not an action that probably will see much use in a very dirty,sandy,muddy etc. conditions.
Kept clean and used for what it's designed for I don't believe it's a concern worth thinking about.
PSI should have nothing to do with it.

Rich
 
Overall pressure (PSI) and consequently excessive friction generated by the large head cases breaking the chromium oxide layer on the locking recesses would have more effect on galling then anything else. Except the use of the same material.

Shoot well
Peter
 
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BAT ships their SS 3L actions with copper-based anti-sieze compound on the bolt lugs & cocking ramp. I considered purchasing some of the same type anti-sieze at the local auto parts store to use, but have never had even the slightest bit of galling in my SS Nesika K using moly-fortified automotive grease on the lugs. My 1st BAT 3L has just under 100rds. of warm 6x47 Lapua through it so far, with no indication of galling. I don't expect any problems with it, nor with the next one, which is chambered for a straight 284W.

The 6x47 is one sweet shooter - can hardly wait to get the 284 up-and-running when the stock gets here.
 
Thanks for all replies

That's all what I wanted to hear.

Shoot well
Peter
 
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