Cryo treatment was all the rage in the 1980's and 1990's. It is intended to stress relieve metal and can prolong the life of engine parts and high wear/stress parts in heavy machinery.
In the gun world, it has little benefit for 99% of rifles once they are assembled. Some manufacturers continue to use the process to relieve stress during the manufacturing process and generally before cutting chambers. Some guys will tell you they can "feel" the difference when cutting chambers.
I do not believe there is much evidence that cryo treatment can make a $hitty shooter suddenly become a sub-MOA wonder weapon. Probably best to save your money and buy a quality firearm.
Never had one done, but know of several. Results varied in those I’ve seen/used, but accuracy never got worse. Didn’t always get better though. No magic there. I was at a gunsmiths when a customer came to pick up a barrel he’d had done, gunsmith had kept the box in his freezer, customer commented it must have been really cold when crepes, because it still was. We had a good laugh.
I have one rifle that has the barrel done. The rifle builder wanted to do it; I was not sure I wanted it done. I thought (at the time it was BS) I can tell you this rifle is a fantastic shooter. But it could be a great shooter even if it wasn't done. This we will never know. Rifle has a Shilen barrel it's chambered in 300 Winchester Mag.
Heck, Pope or Shoyen or one of those guys used to bury barrel blanks in the yard for a few years before rifling them. That was a hundred or so years ago. I think pizzing into the wind through the barrel will be the next thing. Python oil.
Crying treatment does nothing to the barrel dimensionally. At least nothing that can be accurately measured.
If your barrel is effed up for other reasons other than the stresses imparted during the barrel making process, then cryo treating will not improve or fix that. (Rough bore, fouler , variance in bore size crown etc.
Cryo treating cannot fix other problems with the action such as bedding, ignition. Nor the ammunition or the shooter.
Didn't Melvin Forbes credit Cryoing as the reason most of his rifles would shoot so many loads to the same point of impact?
No! Melvin never claimed that, and I have known him since the late 1980s. He did once comment comment to me that cryo made some sense, since like heat-treating it tended to stress-relieve barrels. But he never used it.
Instead he believed the reasons his rifles shot so well were because Douglas used heat to stress-relieve their barrels (as do many button-rifle makers, including Dan Lilja), plus the full-length forend bedding of Melvin's very stiff stocks.
He also thoroughly tested everything he did to confirm his results.
Might also add that all the publicly published articles on cryo-treating I read back when it was all the rage based their conclusions on minor differences in group size, usually on too-few groups.
Have also talked personally with not just John Krieger but other barrel-makers, who concluded cryo made the most difference when done before machining barrels, or at least between certain stages. And yes, they had also done considerable testing.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck