Facts  are facts  suppressors are not magic the baffles and the chambers slow the gas down behind the bullet is what makes it quit the bigger the hole the more gas can ex cape to the next chamber and the bullets as it exists the can  so this is why even if the 45 can has two iches longer baffles and chambers it's still louder with 9 millimeter bullets going through it 
And if gas can surround the bullet it has a chance of causing turbulence which can affect the bullet accuracy hence why you want to stay as close to the  Right  size exiting  hole as the caliper of choice as  possible  . If you shoot a 22 out of a 45 can the gas will follow the bullet out of the bigger holes and not fill the blast chambers like would happen if you had a .230 hole and not a huge 45 hole . Same principal is applied when making a ported muzzle brake you make the hole is close As possible to stop the gas from following and surrounding the bullet making better accuracy letting the gas escape from behind on the break