11 August 2002, 01:46
<HH60AV8R>Tungston Barrels?
I often wonder why Tungston, "the hardest hardest known metal", is not commonly used in Rifle barrels. Iv'e seen some stuff on the net about sleeves. Wouldn't a solid Tungston barrel or sleeve offer unmached stiffnes and life? I realize the stuff must be a pain to machine and of course the price would be an issue. Are there any applications you guys have heard of?
School me up....
Tungsten is heavier than lead. They used tungsten steels in the old firearms of the 1800's. Since WWII the chrome moly and stainless steels have totally replaced the old tungsten steels, being lighter and stronger to boot. I didn't know tungsten was especially hard.
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Titanium anyone?
This would be a good place for a metallurgical engineer to give a little dissertation for us.
11 August 2002, 03:08
<dfaugh>Not an engineer...But expert welder (some time ago) and amateur machinist (Dad was the professional)...Tungsten, well...First, it is SOOooo hard to machine, I can't imagine trying to cut rifling in it for example..It is also extremely brittle, easy to break...Now waht might be interesting would be to "plate" the bore with alayer of tungsten, sort like chrome... I would think this would be very durable, but not at all sure of properties of thin layer tungsten
11 August 2002, 04:36
<HH60AV8R>Thanks for the feedback fellas. I probably should have researched the "hardest of all metals" quote.
11 August 2002, 05:01
<JBelk>A tungsten/cobalt/chrome alloy called "Haynes Stellite" was used as an insert in some military barrels. They were forged and then ground to size an shape and shrunk into the barrel blank. Stellite has no iron in it and is used for it's resistance to heat. It is actually tougher and more wear resistant at 1500 F than at room temp.
What we call tungsten is actually tungsten carbide. It is molded (sintered) to shape and diamond ground if needed.
Actual tungsten is not all that hard (I grind TIG electrodes every day on a bench grinder) or wear resistant.
Tungsten steel alloys usually have less than .25% tungsten unless it's a hot-die work steel which can be up to 19%. Some of the super alloys go higher for special applications.
Machining is a problem with all of them.
Barrel materials are always a trade-off. What makes a barrel last a long time also is very hard to machine. The very best wearing steels are no where NEAR stable enough to shoot more than a one shot group. Everything is a trade-off.
11 August 2002, 05:57
JiriTungsten is used for example as alloy for high speed cutting steels, more tungsten=>harder and more resistant steel but more brittle too. Another way could be stelite/talonite, but how to machine it ??? It could be easy to make knife, maybe shotgun barrel but how to machine grooves ?
For today standards best barrel could be something like christensen arms carbon with steel barrel insert+steel barrel insert coated by titanium nitride. Titanium nitride coating could add up to 10 times higher life to machining tools so what about barrel life ? Problem is that it is made in high vacuum and in electric arc, so it will be hard to coat small caliber barrels inside . . .
Apologize my English please,
Jiri
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