Comments on: Lothar Walther Bi-Metal Barrels Are Lighter, and Shed Heat Better

By: Randolph

Randolph — Sun, 06 Oct 2013 08:22:16 +0000

Mr.T, I doubt that this effort is necessary just for a couple of rounds per minute. Left aside the special purpose of .22lr barrels. Where heat is not a problem at all. Aluminum has about twice the thermal capacity per weight, but also just less than a third the density of steel. So comparing the same volume this combination is prone to have a higher temperature than solid steel. So the only advantage is to carry less weight. Where this kind of barrel has to compete with carbon fiber wrapped barrels.

By: Mr. T

Mr. T — Fri, 04 Oct 2013 14:26:15 +0000

Randolph ,its not like they are meant for machine guns so sheeding heat from couple rounds per minute is no big deal,this is just an alternative to carbon fiber wrapped barrels.

Matt D. that 10-22 bi-metal barrel you had was likely a lothar walther as they are the one making the blanks for many 10-22 aftermarket supplyers.
No aluminum is not nearly as stiff as steel but for given weight ,larger cross section of aluminum tube makes it stiffer that steel barrel of the same weight.

By: Randolph

Randolph — Fri, 04 Oct 2013 14:01:02 +0000

Every time I read such things it makes me smile. The Lewis machinegun had such a barrel, but the intention was to create more surface for air cooling without to much weight. Connecting two materials with different heat expansion provides room for problems. If you want to connect two materials in a thermal effective way, there is one thing you can’t have enough – bearing pressure. And the biggest barrier still remains. For dissipating thermal energy away from the rifle barrel system, air is such a bad medium to do this… Ask engineers dealing with power electronics. Low voltage and high current cause a lot of heat. Especially designers for automotive electronics know about this.

By: Dasher

Dasher — Fri, 04 Oct 2013 11:53:25 +0000

Does it curl around when it warms up like other bi-metals?

Somehow I can never see such a barrel being as accurate as a solid one. Perhaps super application for hunting/tactical, not so much precision.

By: mikee

mikee — Thu, 03 Oct 2013 09:42:01 +0000

Now, if only they would make unchambered barrel blanks!

By: Matt D.

Matt D. — Wed, 02 Oct 2013 23:35:55 +0000

I had a Tactical solutions 10-22 barrel that was like this. Really liked that barrel. This should be very nice. Aluminum is also stiffer than steel so it should have some effect on the rigidity of the barrel.