Let’s assume an unlined, non-surface treated (like Melonite, NiCorr, etc.) piece of steel. Quality alloy steel, but just cold hammer forged. Does cold hammer forging in and of itself have a higher resistance to corrosion than a similar non-lined/treated barrel that is not CHF’d?
Does corrosion take longer to form because of the hardness?
I would imagine it would not make a difference.
It is untreated steel.
I have always heard good steel will corrode just as quickly as the cheap stuff.
There might be a slight benefit because the forging process provides a smoother surface, and smoother surfaces provide less surface area for corrosive reactions and don’t trap any corrosive chemicals as well.
The comparison would depend on the button or cut rifled barrel you’re comparing to. Bot of those processes initially leave a fairly rough surface, but in any quality barrel the bore will be lapped (polished) to reduce that roughness. It’s possible that a high quality button or cut rifled barrel would have a smoother bore after the lapping is done.
I’m not aware of any reason the steel would be chemically more resistant to corrosion after the forging process, only the potential for a physical resistance due to smoothness.
Yeah, I was wondering about the smoothness thing.
I’m referring to the HK MR556 barrel specifically FYI.
Sounds like a chamber brush and a few twists a day under austere conditions (heat, humidity, rain, river crossing, etc.). Granted, I may never be in that scenario but it’s nice to know that perhaps it’s easier to maintain than others; not necessarily more “corrosion-resistant” but less likely to have corrosion form as quickly. i.e. easier to “stay on top” of.
Yugoslav AK barrels were/are cold hammer forged, unlined steel, and corroded and pitted like a mother when subjected to corrosively primed ammo and militias more interested in ethnically cleansing their neighbors than cleaning their weapons.
Steyr in Austria, the pioneer of the “Steyr Process” of cold hammer forging, built the StG-58 for the Austrian military with a non chrome lined bore, to spec. I’ve seen parts kits here from when the Austrian gov’t surplussed their rifles that had worn out bores as well as frosted and pitted bores, and they were using non corrosive Hirtenberger ammo.
Oh I’m not gonna try and convince myself that a non-chrome lined (or even one not treated with something like Melonite) barrel is optimal—not at all. However, perhaps a CHF’d one with it’s inherent “slickness” would be easier to keep clean (?). Like a lot of guys here I want a weapon I purchase to perform under the worst of circumstances, whether or not I will ever experience them. It’s my $$$, I want the “extreme” of function if necessary.
Biggest issue I picture is failures-to-extract under corrosion-welcoming conditions (think Vietnam as opposed to Iraq). The bore itself isn’t as big a concern as the chamber. Granted, calcium carbonate isn’t an issue as an ammo preservative and cleaning kits (namely chamber brushes) are now regularly issued so perhaps it wouldn’t be an issue (?).
There are a lot of non-lined barrels in this country and most aren’t troubled by rust, cold hammer forged or not
Why am I not seeing templars post? [When I am just looking at the thread].
When I respond to the post I see templars post?
I have seen unoiled bores and chambers rust in a single night in foggy areas.
Corrosion is different than erosion.
My LMT with 4150 steel & chrome lining is just starting to show some frosting in the throat area it only has 4k through it.
Most of that is with LC, They all start to wear out sooner or later.
CHF raises the hardness not as much as HC or nitrating but none the less it raises the hardness level which will correspond with the wear rate. The harder it is the less it will wear so yes it does help.
That very well may be, but it’s not a huge problem. It’s usually a light coat and cleans up easily and isn’t heavy enough to damage the steel. The point is, if you have a rifle with steel, unlined bore, take care of it. It’s not that hard. If that’s too difficult, get one with a lined bore and be done with it
Exactly what I was thinking. Worst-case scenario: you are forced (for whatever reason) to survive in summertime in LA or FL. Heck, even a high round-count carbine class in those conditions. A few twists of the chamber brush occasionally should set things right by staying on top of it.
Caveat: some cheap-arse will use 1500rds of Wolf at a class this summer with an HK and have a spent cartridge stick, then they’ll scream bloody murder and others will go “Aha! So the MR556 is a POS!” Wolf will stick in a freakin’ Noveske if conditions are right. The ammo is as important as the conditions for testing.