<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>If, IF, the steel actually had stress in it and we magically removed it in the cryo process, or even if it got removed in an oven, wouldn't the barrel warp to some degree?<HR></BLOCKQUOTE>
Yes, but it might be only an imperceptable amount.
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Is it possible to remove any stress (of any significance) and have a 30" piece of steel 1.250 dia stay straight within .005, like well within).<HR></BLOCKQUOTE>
If the stresses had been almost uniformly distributed around its circumference and along its length, you might not ever see any wrapping after they were relieved. The important thing is for the barrel to heat up uniformly as you shoot. Having the barrel free-floated helps the cooling process. With a forearm that is snug to the bottom half of the barrel, it can't cool as well as the rest of the barrel, so some warping could occur as the barrel cools more on top than the bottom. Of course, the stock can warp from the heating, too.
In 1961, I bought a used Winchester Model 70 in .264 Win Magnum. It had a 26" stainless barrel, and that was my first rifle. God, I wish I had it back!! Shooting off of sand bags with a 6x Weaver scope, I couldn't keep five shots on a 8-1/2" x 11" piece of paper at 100 yards. I asked a local gunsmith about it. He said that some of Winchester's early stainless steel barrels were not properly heat treated and that they warped when being heated from shooting. He said that, even though I bought it used, Winchester still had its name on it and that I should write to Winchester and see what they say. I did, and they said to send it to them...scope, stock, and all. I got it back in about six weeks... with a new barrel ... and no charge. After that, I was getting 3/4" to 1" five-shot groups with 140gr Sierra BTs. How I wish I had that rifle back!!
My original barrel was warping badly after each shot; that was what was scattering the shots all over the paper. Apparently, Winchester had not drawn the steel adequately after the heat-treatment process. Drawing, for non metallurgists and non engineers, is bringing the steel up to an intermediate temperature and allowing it to cool slowly, thus, relieving the internal stresses that were trapped during the previous heat-treatment and quenching operation. Drawing also reduces the hardness, making the steel less brittle, and more ductile and tougher. This is the tempering, or moderation, of the earlier harsh heat treatment that you would get by only quenching the steel. This is the original meaning of the word "temper," which was to moderate, make less harsh, or to reduce the severity of something.
Krieger's website says that cryo-treating reduces the waste, presumably, as you said, from the taper machining operation. The cryo hype says that the cryo treatment makes the steel harder. If that's correct, then the machining operation would be more difficult, not easier. The harder the steel, the harder it is to machine. It could be that the cryo treatment actually improves the machining by making the steel less likely to gall, which could cause unrecoverable errors in machining. I'm guessing on that one.
[ 11-26-2003: Message edited by: CharlieK ]