Stainless vs Chrome moly

Tim N · Post by **Tim N** » Fri Dec 13, 2013 1:12 pm

Hi All,
Given the choice between Stainless and Chrome moly actions which would be better and why?

Seddo · Post by **Seddo** » Fri Dec 13, 2013 1:25 pm

I asked Tony at TSE the same question when i was up there earlier this year.

His reply was if its a hunting rifle then get a CM but if its a target rifle go for SS. He gave me the technical reason but all i remember is the dumb version, with long strings the SS barrels keeps its vertical stringing down for longer than CM when they heat up.

Tim N · Post by **Tim N** » Fri Dec 13, 2013 1:37 pm

Seddo,
Thanks for the reply, but I was thinking about actions.

Brad Y · Post by **Brad Y** » Fri Dec 13, 2013 2:37 pm

Always had chrome moly. I like the blued/black finish on the action with a stainless barrel.

Im no metalurgist, but always thought that stainless was softer and might be a little susceptible to galling lugs etc

GregW · Post by **GregW** » Fri Dec 13, 2013 2:58 pm

Tim,

There are very few Stainless actions around. I think someone made one in Australia, but it was not popular. Why, I don't know. SS cannot be hardened anywhere near as hard as CM. However, the worst actions for "galling" that I have seen are Musgraves and RPA's, and they are very hard. Galling occurs when both surfaces are of similar hardness, assisted, of course, by lack of lube. Omarks and Angels hardly ever gall, as the boltheads are softer than the receiver. The bolthead tends to wear though.
In "the old days" when we used factory ammo, this resulted in loose headspace, particularly in Omarks. I think SS actions are ok for light calibres where there is not the pressures we use, but this is an opinion only.

Greg Warrian.

aaronraad · Post by **aaronraad** » Fri Dec 13, 2013 8:02 pm

Stainless steel actions are normally made from grade 630 stainless steel also known as 17-4 PH stainless steel.

The key is the PH - precipitation hardening which can be performed post machining to bring up the hardness to 40Rc. This is more than you need considering a Barnard's receiver is finished at 38Rc in 4340 (chrome-moly-nickel).

The better stainless steel barrels IMO are also made from 17-4 PH. Higher hardness/lower wear than 416R (designed for machining speed) and higher corrosion resistance than 416R. It's more expensive but nothing comes cheap.