Spitty - We have one of the original Cryo places ( One Cryo ) just down the hill from our shop.
Cryogenic Tempering and Cryogenics Processing Locations of One Cryo
We have sent in some parts before by request, and have found that old, pre'-64 Winchester actions ( that are tough on tooling ) are easier to work if we get them treated first.
If my understanding is correct, it pulls impurities out of the metal, and thus makes it more uniform.
The big ticket item at One Cryo is, or used to be, aluminum softball bats. Something about getting them Cryo'd makes the ball pop off the bat like a shot. We used to get a deal on small parts if we waited for them to fire up the treatment for a load of bats and we got the extra space.
Several manufacturers ( like Kreiger & Lilja ) recommend against treating their barrels as it is not needed for accuracy & barrel life is still speculative.
Lilja Precision Rifle Barrels - FAQ
Some people swear by it. Some people think it's hogwash science. Somewhere in the middle is probably closer to the truth.
If you think it will help, go for it. If can spend the money another way and feel good about it, go that route.
Opinions on this subject are as vast as the world of firearms. You will find people swear by it and people hate it.
I don't know of any barrel getting 5000 rounds of extra barrel life out of it after having it treated. Out of all the records produced by rifles that have left the shop, probably 10% of them had ANY
parts Cryo'd prior to installation.
We do have one guy who gets everything Cryo'd and he swears by it. He does a lot of hunting and a lot of traveling to exotic locales to shoot animals of mystery, so maybe he sees a benefit not readily apparent to the rest of working stiffs.