Quick barrel cooling...yes or no?

[ronsatspokane]

Doing this kind of thing makes we wonder about its effect regarding microcracking of the lands due to rapid contraction of the metal. Though it's not likely to do any major damage to the barrel, it seems like it might speed up the wear and tear of the lands . . .???

That would be a question to be answered with any method of rapid cooling. I can't answer that. Is there a metalurgy expert in the house?

I had a Savage barrel that looked like the lands were cut with a chisel when the barrel was new. It was shooting 1/2 MOA fairly consistently. When it started to go off the thing was fire cracked a third of the way down the barrel. Never use any kind of rapid cooling on it and only shot 20 round strings in F Class. Not so sure that the fire cracking impacts the way it shoots up to a point.

 

[lpreddick]

Doing this kind of thing makes we wonder about its effect regarding microcracking of the lands due to rapid contraction of the metal. Though it's not likely to do any major damage to the barrel, it seems like it might speed up the wear and tear of the lands . . .???

My barrel is a Kreiger that was cryoed before cut rifled. This process involves liquid nitrogen at near 300 degrees below zero. Granted this was done as a blank. My cooled water is around 45° and i used 98 ° or so as an endpoint before cooling. One can run water down the bore slowly and i doubt any harm is done.

 

[Straightshooter1]

I had a Savage barrel that looked like the lands were cut with a chisel when the barrel was new. It was shooting 1/2 MOA fairly consistently. When it started to go off the thing was fire cracked a third of the way down the barrel. Never use any kind of rapid cooling on it and only shot 20 round strings in F Class. Not so sure that the fire cracking impacts the way it shoots up to a point.

I think the microcracking has more to do with the expansion and contraction of the barrel due to the pressure changes than heat. But because there is that expansion and contraction, I wonder about the effect (if any) the speed of the change has on the microcracking.

Other than the minute and slow loss of material from microcracking, it doesn't seem to impact shooting results except over a period of time depending on the number of firings and the pressures being used.