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.
