A thou ain't gonna make a bit of difference in jacketed pistol bullets. Could be measurement or instrument error, but it would not surprise me none if they really are .450. I've run into bullets smaller than the box was marked, .32 specials, in particular.
Does make a difference with lead bullets, too.
PS, there is a fair chance that you got sold repackaged seconds. Shoot them anyway. Ain't gonna hurt nothing.