On Sat, 23 Feb 2013 22:29:08 -0800 (PST), Stanley Schaefer
wrote:

On Feb 23, 2:56*pm, clark wrote:
That steel can get incredibly hard if it gets hot, but the barrels are not very hard at all.

Why pay extra for tool steel?

TIA

Don't want HARD, want tough and more important, want a material that
resists erosion from very hot, very high velocity and very high
pressure gas. And what the commercial barrel makers order for steel
isn't 4140 that you get from the local steel merchant. Since they
order tons at a time, they can get an alloy that does the same or
better for physical properties, but is easier to machine and pull
buttons through. If you had a super-hard barrel, it'd probably
grenade, too brittle to take the near-instantaneous pressure load.
Some army officer had the same bright idea, I've got a book that shows
the results of putting case-hardened throats in cannon. Didn't last
more than a few rounds before they shattered. And 4140 is hardly
"tool steel". High chromium and nickel content cuts gas erosion
considerably, back in the early days of smokeless powder, they found
that plain carbon steel barrels that were fine for black powder and
lead bullets just had their rifling go away in a few hundred shots.
Winchester used nickel steel for the first time in their 1894 .30-30
barrels for that reason. A big deal in the late 1890's, using an
alloy steel.

There are a few books out there on barrel making, most are short run
printings, but can be had. I've got a couple.

Stsn

I wonder how P-7 would work for gun barrels?


The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie