SS -vs- steel barrels

416 is a high sulphur version of 410 --easier to machine .416R is made by Crucible and is a 416 with more precisely controlled amounts of sulphur. Military barrels at one time were 4140R ,again high sulphur for easier machining .
Krieger barrels were cryogenically treated [ today ? ] but never proved by me the metallurgist or many others.If it had been all the custom makers would be using them !
BTW 416R is good down to -40 F !
 
Yes, the resonant frequency differs; a tiny, insignificant amount. So does the heat expansion ratio. I'll calculate the resonant freq difference when I get access to my software. It's the third or fourth harmonic and barrel time that determines muzzle axis angle at bullet departure. But it's very repeatable for a given barrel and load; that's what matters. Later.......

It's the same as claiming higher velocity is better than slower for better accuracy. Stiffer barrels resonate at higher frequencies.
 
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Barrel whip, for one. A softer metal tends to flex more. Watch a slo-mo vid of an AR vs AK sometime.
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I'm going to call this on to task. I don't know AK vs AR, but I know something about steel.

Given 2 barrels of identical dimensions, and dissimilar materials, the one with the higher modulus of elasticity will be stiffer. I think steel and stainless are the same... no, carbon steel is clearly better 29 vs 27.6....actually, this is pretty close. I think I used 30 for both all through school and got lots of A's!

Given a softer barrel and a harder barrel, the softer one will have a lower ultimate tensile strength.

What does this tell me about best barrel? Nothing! Talk to a barrel maker to get that info.

Fundamentally, barrel life is determined by crown damage and fracture toughness of the throat at elevated temperatures. Temp is the key variable and is driven by chamber design, rate of fire and velocity of the bullet.

Knowing those answers can allow your barrel maker or you to hone in on the right barrel material.....or you can match your gun....pretty is often the best way to decide!:eek:
 
There's a really interesting article about barrels you should take a look at. It's primarily from the benchrest shooting perspective, but it covers everything from types of steels used, to contour, twist rates, types of rifling, grooves, fouling, fluting, etc. That article should answer any question you might have. Go to: http://www.6mmbr.com/barrelFAQ.html

Dave
 
Fundamentally, barrel life is determined by crown damage and fracture toughness of the throat
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This is were I believe SS might have the edge over carbon steel. The nickel content, among other things, makes it more wear resistant than carbon. Might not be an exact analogy but if you have sharpened a carbon steel knife and a SS knife on the same stone it takes a lot longer to wear down good stainless to a sharp edge.
 
Chaz88,

If you had a stainless or carbon steel barrel anywhere near the Rockwell hardness of a decent blade it would shatter on firing.

All of the stainless steels used for blades are tool steels, which mean they are formulated for hardness and edge holding ability, not resilience in the face of 60,000 psi of peak pressure.

The closest you can get to a really hard surface in a barrel is chrome or nitriding (ie melonite). Even then you are only extending the useable life of the barrel by a fraction of the uncoated barrel (but up to 100% depending on how hard/fast you shoot through it).

Jimro
 
Might not be an exact analogy but if you have sharpened a carbon steel knife and a SS knife on the same stone it takes a lot longer to wear down good stainless to a sharp edge.
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Knife steels do not related to gun barrel steels. Also, it depends on which knife steels you are talking about. Further, "stainless steel" is a group of over thirty steels (as of about 1985, likely more now), with different properties. Also, as I remember, custom, top of the line knives had pretty much abandoned 440 C stainless for more exotic steels like 154 CM and D2. Your experience with your knives is not all that relevant to gun barrel steels.
 
I think that there are some wrong assumptions going on here.
For example Nickel is very soft and does not wear at all well. Nickel is used in SS because its very resistant to corrosion, heat and chemicals. Unless we are talking about 400 series (martensitic/ferritic) which contain carbon and iron or in some cases duplexing alloys like 17-4. Austenitic alloys 300 series are very soft. Cheep knives like the ones from China that are stamped stainless do not form a good edge or hold any kind of edge. Higher quality special alloys like Buck (S2??) do hold an edge and are difficult to sharpen. But most quality knives are made from carbon steels. Some are now using D-2 tool steel wich offers extreme hardness and reasonable corrosion resistance due to the chromium content.
Chrome or other lined barrels use a hard coating with a soft base material.
 
A. We buy our steels directly from the steel mills. Our steel is made to our specifications as far as chemistry and heat treatments are concerned. Our chrome-moly is a modified 4140 type steel and the stainless steel is type 416 with a few extra steps and tests in its manufacture. We have used steel of both types from several different mills and have settled on what we feel is the best available.
The primary difference between the two types, as far as rifle barrels are concerned, is that chrome-moly can be blued and stainless steel cannot, using conventional methods. Rifle barrels made from stainless steel will last longer, as related to throat erosion, than chrome-moly. Stainless steel resists heat erosion better. Also we can get a slightly better internal finish when lapping with stainless steel.
Approximately 90% of the barrels we manufacture are made from stainless steel. In our experience, most of the chrome-moly barrels we make go on high-grade custom hunting rifles that are going to have a nice custom made wood stock. And some shooters insist on having a blued barrel.

An exception to the above is the large number of 50BMG barrels we make from chrome-moly. Our recommendation for steel choice with 50BMG barrels depends on the bullet type the shooter intends to use. If you are going to use conventional jacked bullets, such as the Hornady or ball ammunition, then the stainless steel barrels will probably last longer and foul less. But if your choice is one of the custom made lathe-turned bullets made from brass, bronze, copper, or even steel, then the chrome-moly barrels will probably last longer and give better accuracy. Please see our comments on moly coating and these types of bullets. If you plan to shoot both types of bullets then the chrome-moly barrels are a better choice
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This is from Lilja barrels
 
I think I indicated that it was not an exact analogy. Nickel alloyed is not the same thing as nickel on its own. That is the point of making alloys. If we are just talking about the mentioned 416 it is irrelevant because it is not alloyed with nickel. It has sulfur to help with machining. It is mostly chromium that makes stainless corrosion resistant.
 
I've had a 700 Rem stainless, .270 Win. for about 20 years and don't have issues with the barrel, but noticed minor battering of the action where the bolt handle cam hits it upon extraction. The blued actions I've had showed no such battering.

I was told by a competition shooter that he recommends blued actions for rifles to be shot a lot and stainless for those to be exposed to elements more than shot at the range.

The blued actions also seem to exhibit a little less friction than the three stainless ones I have.
 
I have no idea which is more accurate or which lasts longer. What I can tell you is that seeing a chrome moly barrel at a bench rest match is about as rare a seeing a unicorn in my cow pasture. There is either a good reason for it or everyone has bought into a myth. I could not honestly tell you which is correct.
 
From what I have seen, it comes down to cheap manufacture. I really don't remember seeing a whole lot (Or any) of "Cut" stainless barrels out there over the years. The big change over to button rifling really started the ball rolling on stainless use. 416 galls easily and I imagine it would be a nightmare to pull a broach through an area that long and retain some kind of a decent finish. Most barrel steel is about like brake steel, around 28 RC. This does seem to ease the galling somewhat when machining, but it is still hard on tooling. I remember one barrel maker advertising their 4140 as "Resulpherized", as if it was a good thing. In my opinion that is nothing more than adding dirt to the steel to make it machine easier. In the end it usually comes down to cost/machinability of a material.
 
Cut rifled barrels have been used to win matches and set records for decades. Obermeyer, Kreiger, Bartlein, Border and others. They've become more popular for benchrest competitors in the last few years.
 
It's pretty common knowledge that stainless is softer than these carbon steels...
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That's only true when both are hardened to their maximum hardnesses. Gun barrels are left very soft (relative to knife blades, for example) which means they are nothing near the maximum hardness that could be attained with the alloys used.

Gun barrels are as hard as the maker wants them to be, regardless of the material used.
 
Bart B, Are the newer cut barrels stainless? I was not down grading cut rifling, just stating that button rifling seemed to have a major influence on the big shift to stainless barrels.
 
Yes, those cut rifled barrels are stainless. Some 316R and some 416R.

Hart 30 caliber button rifled barrels were favored by high power match rifle folks until Al Hauser (their best barrel maker) retired in the late 80's and Kreiger's cut rifled ones were the only ones that shot as good as those. Hart's have been not all that popular any more, at least as far as I know.
 
Hart Barrels haven't been dominating the competitions lately, but every once in a while one will show up on the line. Krieger and Bartlein are the two big names for the tactical competitions.

But I wouldn't dismiss a button rifled barrel out of hand. According to 6mmbr.com, David Tubb uses Schneider barrels exclusively, which are button rifled.

Jimro
 
I asked David Tubb about his use of Schneider barrels years ago; known him since the late 60's as well as his Mom and Dad. He said they made the bore and groove diameters like he wanted and didn't mind them lasting half as long as the other button or cut rifled ones producing top accuracy levels. Others producing top scores had tried Schneider barrels finding them equally good but lasted half to two thirds of what Hart or Obermeyer barrels did.
 
Bart B.,

That's the rub. Steel that is easier to machine is easier to make uniform, but it also won't last as long...

I think that might be why nitriding is getting so popular, although I haven't seen any good studies on actual wear reduction or increase in life span.

Jimro
 
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