SR420, there is a problem with that claim. Benchresters don't seem to have a problem with blast waves disturbing their bullets shooting in the zeros winning matches and setting records. Neither does any other competitive shooting discipline's barrels without supressors on them. Blast waves at the muzzle do not change bullet's flight when they're even all the way around them.
And dampening out barrel whip doesn't improve accuracy. If it did, then long, skinny and whippy 30 inch barrels would not shoot 155-gr. bullets from .308 cases as accurate as short, thick, stiff ones do.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master