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View Full Version : Difference in LW-50 steel and 4160 Steel for Barrels


dlouie87
10-30-2008, 3:18 PM
I was just wondering the pros and cons to these two types of steel. It's going to be for a Stainless steel barrel.

Larue uses LW-50

and WOA uses 416...

Just wanted some insight.

This is what I found:

"In the late 1980's, it was realized that there were erosion and short barrel-life problems with 416 Stainless in the calibers operating at 65K psi. 410 Stainless also had issues. LW-50 became the answer. LW-50 lacks sulphur, which in high quantity, created short throat-life in other Stainless Steels. LW-50 can also be heat-treated to a point that makes it near-optimal in all forms of rifle barrels. LW-50 has been proven for over 15 years, in military and civilian uses ranging from sniper, tactical, target, and other high-performance applications where long life and accuracy are critical."

can some elaborate?

-Dan

asheron2
10-30-2008, 3:28 PM
If thats an AISI-SAE Designation

4160 is an alloy steel. The 41XX is for Nickel-Chromium-Molybdenum Steel.
So its not even stainless.

Please correct me if im wrong guys, thanks

Also found this:



"To achieve the high strength the steel must possess to withstand the forces produced during firing, AISI 416 SS and/or AISI 4140/4150/4340 must be austenitized, quenched and tempered. After quenching, the average 416 SS will be about 40 Hardness Rockwell C (HRC) and 4000 grades about 50 HRC (To benefit those who do not know this scale, a file will be about 60 HRC, and a hammer will be about 30 HRC). In the "as quenched" state, the material is brittle and unstable. Tempering is employed to reduce the hardness to a "tough" state and stabilize the newly formed martensitic structure. In the case of 416 SS, and to get the hardness to about HRC 30 so it is able to be machined, one must temper at about 1075F. This is not desirable as 416 SS shows a marked reduction in impact resistance when tempered between 700F and 1100F (temper imbrittlement). It will also show a marked decrease in corrosion resistance. 416 SS does still however exhibit better wear characteristics and corrosion resistance than the 4000 series high-strength grades mostly due to the higher chromium content. It is also readily available, inexpensive, and it looks good so manufacturers use it. The big problem though is that it is not as free-machining as the 4000 series grades so generally sulphur is added to alleviate that problem. What you then have is a microstructure with "sulphide stringers" in it that has been tempered in a bad tempering range so the impact resistance of the steel is very poor. Failures happen, and are not really wide-spread, but I will not buy a 416 SS barrel for that reason. The AISI 4140/4150/4340 grades do not have this temper imbrittlement problem, and show superior impact resistance when tempered to about 30 HRC. They are cheaper to buy in a production rifle. One who takes good care of a firearm will never have any major corrosion and wear issues with the 4000 grade steel barrels anyway. And if you do use it an awful lot and it begins to wear out, well then you got your money's worth from the product, just buy a new barrel. Nothing lasts forever anyway. As a note, AISI 410 SS is a better alternative to 416 SS as is does not generally have the sulphur issue, however the temper imbrittlement issue is still a concern.

Here is my opinion: Unless you are competition shooter, buy the non-stainless grade barrels. If you are a professional match shooter find a good AISI 17-4PH barrel as it is a much better choice if one wants corrosion resistance, wear resistance, and impact resistance.

For my money and safety, it is a 4000-series material."

dlouie87
10-30-2008, 6:33 PM
hmmm...so many decisions...

jandmtv
10-30-2008, 6:50 PM
4160 is chromo steel
416 is stainless

dlouie87
10-30-2008, 8:07 PM
4160 is chromo steel
416 is stainless

i'm trying to compare 416 to LW-50 is there a difference? I know they are both stainless....WOA uses 416 for their barrrels and Larue has lw-50 stainless steel. I was wondering the advantages of one or the other.

Fjold
10-30-2008, 8:32 PM
LW50 is also used extensively by Lothar-Walther for their barrels and they have a reputation for long life. It is much harder to machine though and a lot of gunsmiths don't like it.

Lothar-Walther will send you special machining instructions with the barrel blank when you buy it but many gunsmith's egos won't let them admit that they don't know it all so they don't bother to read them and you wind up with rough chambers and bad throats.

Addax
10-30-2008, 8:38 PM
I believe LaRue is using the Lothar Walther Barrels.

buffybuster
10-30-2008, 8:39 PM
I might be wrong, but I believe LW-50 is Lothar-Walter's designation for 17-4 stainless. If so, then it is quite excellent in the application as gun barrel steel.

sb_pete
10-30-2008, 8:44 PM
I think POF also uses LW-50. Might be wrong about that one though :shrug:

Pryde
10-30-2008, 8:47 PM
I have been told that 410 stainless is the best barrel material. The reason why you don't see it much is because 410 is a lot harder to machine than 416 which is a softer alloy.

FWIW, Sabre Defence makes their barrels out of 410 and apparently are easily on par with anything made by the small boutique manufacturers accuracy-wise.

buffybuster
10-30-2008, 9:29 PM
I have been told that 410 stainless is the best barrel material. The reason why you don't see it much is because 410 is a lot harder to machine than 416 which is a softer alloy.

FWIW, Sabre Defence makes their barrels out of 410 and apparently are easily on par with anything made by the small boutique manufacturers accuracy-wise.

410 is pretty much 416 without the sulfur. The sulfur was added to make it free machining, but as stated earlier this can leave sulfur stringers.