Ok, lots of misinformation out there. If the barrel were to get to 800*, then you water quenched it, there could be some warping.
this is the basic unit:
pepsi bottle, oil bottle attachment($4) available at Wal Mart and most auto part stores,
Sinclair rod guide($20)
We have used mountain dew, diet pepsi, 7 up
TIGHT FIT
about 6 oz of water is all it takes, then follow by using 4 dry patches on a PUNCH type of jag, then dry the chamber. Since you have the bore guide on the end of the unit, things are simple
Also, as you are dry patching the barrel out, a lot of loose carbon comes out. Your shooting strings are extended using this method.
We have used this method on the finest custom rifle barrels made along with Rem, Savage, Ruger, and Winchester factory barrels. None of the barrels have been harmed since the late 80's.
If this method scares you, or is inconvient, then douse the outside of the barrel with a 50/50 solution of water and rubbing alcohol to the point to where the water is dripping off the bottom.
The old tried and true method of rotating guns with the bolt open standing up, just does not work, we tried that and ended up wasting barrels(shot too hot, would not cool in temps of 90*+) on good dog towns, barrels never cooled and we had 6 guns each.
Till some idiot gun writer publishes an article on how effective this is, not one will accept it.
After I quit shooting Benchrest, I would take my Hall M actions with McMillen stocks and Hart barrels and just fill the barrel channel full of water on hot dog towns, never hurt a thing...but the dogs!!! With the left port and right bolt, pulling the trigger with my middle finger, I could accurately place shoot 5-6 rounds a minute, with rarely ever missing. It was so hot at times, we had no clothing but our bathing suits. We shot in the shade of the tarp.
I finally got the picture posting thing down pat, about time....