barrel question

[pulserifle99]

[C.G.]

It really depends on who made the barrel and which chrome moly. The stainless steel should last longer, however.

[CRTguns]

It really depends on who made the barrel and which chrome moly. The stainless steel should last longer, however.

Very very wrong... Stainless by nature is more resistant to corrosion- atmospheric, caustic, etc... NOT erosion due to friction and heat. Stainless WILL wear out faster.

The SS alloys used in barrels are even a little lighter by the same volume than a good chrome moly steel.

Notice that our military has never uses Stainless in any small arms gun barrel. Granted, the "big guns" on battleships use SS, but a specially prepared alloy using a process called passivation that goes a step further to make the steel 100% proof against erosion and corrosion.

A lot of the mirror polished rifles you see on the benchrest line are in fact CM steel- left white and polished to a smooth non-porous surface. CM steel left "in the white" can last ages without rusting.

Stainless will always make some sacrifice in order to make a gain. Go for better machineability for a more precision part, and the steel is not 100% rust proof. Go for a SS alloy that is 100% rustproof, and it will be grainy and show excessive material relief during machining- makes precision difficult. Get a SS alloy that is 100% resistant, and free machining, your steel will gall easily or crack due to a more brittle structure.

Just my 200,000,000 cents worth.

I'll concede though, that 2 pieces of metal left on the beach, one carbon steel, and one stainless steel, the stainless will still be there for eons to come- under natural circumstances.

[C.G.]

Very very wrong... Stainless by nature is more resistant to corrosion- atmospheric, caustic, etc... NOT erosion due to friction and heat. Stainless WILL wear out faster.

The SS alloys used in barrels are even a little lighter by the same volume than a good chrome moly steel.

Notice that our military has never uses Stainless in any small arms gun barrel. Granted, the "big guns" on battleships use SS, but a specially prepared alloy using a process called passivation that goes a step further to make the steel 100% proof against erosion and corrosion.

A lot of the mirror polished rifles you see on the benchrest line are in fact CM steel- left white and polished to a smooth non-porous surface. CM steel left "in the white" can last ages without rusting.

Stainless will always make some sacrifice in order to make a gain. Go for better machineability for a more precision part, and the steel is not 100% rust proof. Go for a SS alloy that is 100% rustproof, and it will be grainy and show excessive material relief during machining- makes precision difficult. Get a SS alloy that is 100% resistant, and free machining, your steel will gall easily or crack due to a more brittle structure.

Just my 200,000,000 cents worth.

I'll concede though, that 2 pieces of metal left on the beach, one carbon steel, and one stainless steel, the stainless will still be there for eons to come- under natural circumstances.

You say very, very wrong.

1) Chromelined was left out of this equation and that is what the US military uses for a good reason. By a long shot it will outlast chromemoly or stainless.
2) The US military has rarely if ever used chromemoly, same with stainless, at least since Vietnam.
3) SS is easier to machine than chromemoly, I'm told by machinists, so the tolerances are tighter.
4) There are different kinds of chromemoly and different kind of stainless steel. Each has its application. Sometimes the wrong steel is used for the wrong reasons (mostly cost). Hence I wrote "it depends".
5) I am not going to argue that chromemoly is bad, but how many benchshooters choose ss over chromemoly?
6) There is a process now, finally getting to mainstream, to chromeline ss barrels, which may turn out to be a good alternative.

This is my .000000000000000000000000000000000000000000000002 cents worth, but then again I don't sell guns.

BTW, we have a saying:
stainless isn't (and if you believe it is I have a bridge to sell you).

[ar15barrels]

If you were to expend the same effort in making a barrel from chromoly and stainless steel, the stainless steel one will be more consistent and hence more accurate.
You can certainly have a chromoly barrel be accurate too, it just takes more effort than a stainless barrel does.
That's why almost all high-end barrels are made from stainless steel.

Chromoly is more resistant to cleaning rod damage, but gets brittle with the heat of combustion and this brittleness is what allows the throat erosion to take place.
Stainless is more resistant to erosion, but more likely to be damaged by a cleaning rod.
Chrome-lined chromoly is most resistant to erosion and cleaning rod damage, but least likely to be accurate.

[ocabj]

For the most part, Stainless Steel barrels are more accurate than Chrome Moly and Chrome Lined (CM) because SS rifling is easier for barrel makers to work with. They can consistently cut the rifling on SS with tighter tolerances and thus, can guarantee more consistent quality out of SS barrels.

That said, Northern Competition is one company that manufacturers barrels (AR15) using Chrome Moly steel and everyone who uses those barrels are very happy. NC claims longer life over SS barrels because the steel gets harder after break-in. I have no idea where the science is in this, but that's what they claim and people are happy with NC quality.

Personally, I'd get SS if accuracy is the utmost importance. Get yourself a Schneider or Mike Rock 5R barrel and you'll be all good.

[m24armorer]

Quote: Notice that our military has never uses Stainless in any small arms gun barrel. Granted, the "big guns" on battleships use SS, but a specially prepared alloy using a process called passivation that goes a step further to make the steel 100% proof against erosion and corrosion.

The USMC M40A1/A3's all have stainless barrels so do the Armys M24 SWS.

[ar15barrels]

The USMC M40A1/A3's all have stainless barrels so do the Armys M24 SWS.

...because of the improvement in accuracy that the high quality barrels provide.

When you start looking at high quality barrel blanks, most of the makers either recommend or flat-out only use stainless steel.

[supersonic]

If you were to expend the same effort in making a barrel from chromoly and stainless steel, the stainless steel one will be more consistent and hence more accurate.
You can certainly have a chromoly barrel be accurate too, it just takes more effort than a stainless barrel does.
That's why almost all high-end barrels are made from stainless steel.

Chromoly is more resistant to cleaning rod damage, but gets brittle with the heat of combustion and this brittleness is what allows the throat erosion to take place.
Stainless is more resistant to erosion, but more likely to be damaged by a cleaning rod.
Chrome-lined chromoly is most resistant to erosion and cleaning rod damage, but least likely to be accurate.

Randall: YOU were the ONLY one (as suspected) to hit the nail on the head (almost)!!!! your last two words should have been separated by the word "as." Otherwise, 100%
S.S.

[ar15barrels]

Randall: YOU were the ONLY one (as suspected) to hit the nail on the head (almost)!!!! your last two words should have been separated by the word "as." Otherwise, 100%
S.S.

The descriptive term "accurate" is ALWAYS relative so the "as" is not required.
Intelligence is necessary and assumed here, but not guaranteed.

[supersonic]

The descriptive term "accurate" is ALWAYS relative so the "as" is not required.
Intelligence is necessary and assumed here, but not guaranteed.

Eye gess yur rite.
S.S.

[C.G.]

The USMC M40A1/A3's all have stainless barrels so do the Armys M24 SWS.

Good to know, thanks.

[CRTguns]

Well, I'm basing what I say on what the experts say- I mean the guys that make their living making the best barrel for its job.

Chrome lining is the best way to ensure a bbls life, granted. Till recently though, this could not be done on a SS pipe- Noveske is the first one to make it fly.

Stainless galls because of its open, sponge-like molecular structure. It is lighter because of its open molecular structure. Certain SS alloys can actually "de-alloy" with UV exposure- to a very shallow depth of course.

Dave Manson, of Manson reamers makes this same argument- and will make certain changes to a reamer's geometry to allow for the problems with SS.

The heat absorbtion and threshold of CM is higher than SS.

SS, given the same surface finish as a like piece of CM, has a higher friction coefficient- open grain structure- not a good thing for the inside of a barrel.

I own a borescope- I can see the results in the throat erosion- and the straitions in griives and on lands. I can see the fouling and buildup and wear...

People, I'm not trying to sell you a CM barrel- I'm telling you what I've learned from a lot of 1000yd shooting experience, and rifle-building and experimentation and research and talking to the experts.

I'll admit that in the hands of most shooters, these slight differences will hardly ever be realized- most don't shoot enough or just dont shoot well enough to see the real world results...