uh, yes, physics does tell us this. but don't take my word for it, just look at benchrest comp shooters, shooting 12 lb 22's, with barrel tuners on the front as heavy as a car disc brake.
all bbls , no matter how tiny a cartridge is fired down them, go through a set of laws governed by internal ballistics, a huge field of work that everyone in firearms development put s a ton of research into. Every bbl, goes through bbl whip, as an object moves down it's bore, every bbl also is subject to harmonics, basically the wave created by the projectile passing down the bore. And there are other things as well, such as heat, cooling time, deflection, outside temps, metal core temps, humidity, direct sunlight, wind shear, we can go on, and on. All these things effect bbl accuracy , all of them, on every shot.
A thicker , stiffer bbl, on any weapon, helps to reduce the effects of all these fields of thermodynamics, fluid dynamics, flow dispersion aerodynamics, etc. And the more we can reduce these factors , the more accurate a bbl can be, all things being equal, even with a sloppy chamber, and a sloppy made bore. a fat stiff bbl, can even help a ruger 10.22, God willing, with it's accuracy.
am I saying a thin bbl cannot shoot accurately? Oh contrare, I have several that do, but if I heat them up, or shoot more than about 5 groups in a row, even with 1 minute waiting periods between shots, they will not keep up with my heavy bbl 22's, which I have in Marlin, Savage, Cz , and ruger, and a long bbl pistol by Anschutz